Copyright (c) 1992 Association of Mizar Users
environ vocabulary PRE_TOPC, EUCLID, FINSEQ_1, GOBOARD1, FINSEQ_4, RELAT_1, INCSP_1, MATRIX_1, TREES_1, BOOLE, FUNCT_1, ARYTM_1, ABSVALUE, MATRIX_2, TOPREAL1, GOBOARD2, MCART_1, TOPREAL4, GOBOARD4; notation TARSKI, XBOOLE_0, ZFMISC_1, SUBSET_1, NUMBERS, XREAL_0, REAL_1, NAT_1, FUNCT_1, FINSEQ_1, STRUCT_0, PRE_TOPC, ABSVALUE, FINSEQ_4, MATRIX_1, EUCLID, TOPREAL1, TOPREAL4, GOBOARD1, GOBOARD2; constructors REAL_1, NAT_1, ABSVALUE, TOPREAL1, MATRIX_2, TOPREAL4, GOBOARD2, FINSEQ_4, INT_1, MEMBERED, XBOOLE_0; clusters GOBOARD1, RELSET_1, GOBOARD2, STRUCT_0, EUCLID, INT_1, MEMBERED, ZFMISC_1, XBOOLE_0, NUMBERS, ORDINAL2; requirements REAL, NUMERALS, BOOLE, SUBSET, ARITHM; definitions TARSKI, GOBOARD1; theorems AXIOMS, TARSKI, REAL_1, NAT_1, ZFMISC_1, FINSEQ_1, ABSVALUE, SQUARE_1, FINSEQ_2, REAL_2, MATRIX_1, TOPREAL1, TOPREAL4, GOBOARD1, GOBOARD2, RLVECT_1, FINSEQ_3, FINSEQ_4, PROB_1, GROUP_5, FUNCT_1, PARTFUN2, INT_1, XBOOLE_0, XBOOLE_1, XCMPLX_0, XCMPLX_1; schemes NAT_1, GOBOARD2, GOBOARD1; begin reserve p,p1,p2,q1,q2 for Point of TOP-REAL 2, P1,P2 for Subset of TOP-REAL 2, f,f1,f2,g1,g2 for FinSequence of TOP-REAL 2, n,m,i,j,k for Nat, G,G1 for Go-board, x,y for set; theorem Th1: for G,f1,f2 st 1<=len f1 & 1<=len f2 & f1 is_sequence_on G & f2 is_sequence_on G & f1/.1 in rng Line(G,1) & f1/.len f1 in rng Line(G,len G) & f2/.1 in rng Col(G,1) & f2/.len f2 in rng Col(G,width G) holds rng f1 meets rng f2 proof let G,f1,f2; assume A1: 1<=len f1 & 1<=len f2 & f1 is_sequence_on G & f2 is_sequence_on G & f1/.1 in rng Line(G,1) & f1/.len f1 in rng Line(G,len G) & f2/.1 in rng Col(G,1) & f2/.len f2 in rng Col(G,width G); defpred P[Nat] means for G1,g1,g2 st $1=width G1 & $1>0 & 1<=len g1 & 1<=len g2 & g1 is_sequence_on G1 & g2 is_sequence_on G1 & g1/.1 in rng Line(G1,1) & g1/.len g1 in rng Line(G1,len G1) & g2/.1 in rng Col(G1,1) & g2/.len g2 in rng Col(G1,width G1) holds rng g1 /\ rng g2 <> {}; A2: P[0]; A3: for k st P[k] holds P[k+1] proof let k such that A4: P[k]; let G1,g1,g2 such that A5: k+1=width G1 & k+1>0 & 1<=len g1 & 1<=len g2 & g1 is_sequence_on G1 & g2 is_sequence_on G1 & g1/.1 in rng Line(G1,1) & g1/.len g1 in rng Line(G1,len G1) & g2/.1 in rng Col(G1,1) & g2/.len g2 in rng Col(G1,width G1); A6: dom g1 = Seg len g1 & dom g2 = Seg len g2 by FINSEQ_1:def 3; defpred P[Nat] means $1 in dom g2 & g2/.$1 in rng Col(G1,width G1); A7: ex m st P[m] proof take n=len g2; thus n in dom g2 by A5,FINSEQ_3:27; thus thesis by A5; end; consider m such that A8: P[m] & for i st P[i] holds m<=i from Min(A7); set g = g2|m; A9: 1<=len g by A8,GOBOARD1:38; A10: g is_sequence_on G1 by A5,GOBOARD1:38; A11: g/.1 in rng Col(G1,1) by A5,A8,GOBOARD1:22; A12: g/.len g in rng Col(G1,width G1) by A8,GOBOARD1:23; 0<>width G1 & 0<>len G1 by GOBOARD1:def 5; then A13: 0+1<=width G1 & 0+1<=len G1 by RLVECT_1:99; then A14: 1 in Seg width G1 by FINSEQ_1:3; A15: width G1 in Seg width G1 by A13,FINSEQ_1:3; A16: 1 in dom G1 by A13,FINSEQ_3:27; A17: len G1 in dom G1 by A13,FINSEQ_3:27; A18: 1 in dom g by A9,FINSEQ_3:27; A19: dom g = Seg len g by FINSEQ_1:def 3; reconsider L1 = Line(G1,1), Ll = Line(G1,len G1) as FinSequence of TOP-REAL 2; defpred P[Nat] means $1 in dom G1 & rng g /\ rng Line(G1,$1) <> {}; A20: ex n st P[n] proof consider i such that A21: i in dom Col(G1,1) & g/.1=Col(G1,1).i by A11,FINSEQ_2:11; A22: i in Seg len Col(G1,1) by A21,FINSEQ_1:def 3; take i; len Col(G1,1)=len G1 & len Line(G1,i)=width G1 by MATRIX_1:def 8,def 9; then A23: dom Line(G1,i) = Seg width G1 by FINSEQ_1:def 3; i in Seg len G1 by A22,MATRIX_1:def 9; hence i in dom G1 by FINSEQ_1:def 3; then g/.1=Line(G1,i).1 by A14,A21,GOBOARD1:17; then g/.1 in rng Line(G1,i) & g/.1 in rng g by A14,A18,A23,FUNCT_1:def 5,PARTFUN2:4; hence rng g /\ rng Line(G1,i) <> {} by XBOOLE_0:def 3; end; A24: for n st P[n] holds n<=len G1 by FINSEQ_3:27; consider mi be Nat such that A25: P[mi] & for n st P[n] holds mi<=n from Min(A20); A26: dom G1 = Seg len G1 by FINSEQ_1:def 3; consider ma be Nat such that A27: P[ma] & for n st P[n] holds n<=ma from Max(A24,A20); defpred P[Nat] means $1 in dom g1 & g1/.$1 in rng Line(G1,mi); A28: 1<=mi & mi<=len G1 & ma<=len G1 by A25,A27,FINSEQ_3:27; then A29: ex n st P[n] by A5,GOBOARD1:45; A30: for n st P[n] holds n<=len g1 by FINSEQ_3:27; consider ma1 be Nat such that A31: P[ma1] & for n st P[n] holds n<= ma1 from Max(A30,A29); A32: 1<=m & m<=len g2 by A8,FINSEQ_3:27; then A33: len g = m by TOPREAL1:3; A34: rng g c= rng g2 proof let x; assume x in rng g; then consider n such that A35: n in dom g & x=g/.n by PARTFUN2:4; n in Seg m by A33,A35,FINSEQ_1:def 3; then x=g2/.n & n in dom g2 by A8,A35,GOBOARD1:10; hence thesis by PARTFUN2:4; end; reconsider Lmi = Line(G1,mi) as FinSequence of TOP-REAL 2; A36: mi=ma implies rng g1 /\ rng g2 <> {} proof assume A37: mi=ma; consider n such that A38: n in dom g1 & g1/.n in rng Line(G1,mi) by A5,A28,GOBOARD1:45; consider i such that A39: i in dom Line(G1,mi) & g1/.n=Lmi/.i by A38,PARTFUN2:4; A40: dom Line(G1,mi) = Seg len Line(G1,mi) by FINSEQ_1:def 3; reconsider Ci = Col(G1,i) as FinSequence of TOP-REAL 2; A41: len Line(G1,mi)=width G1 & len Col(G1,i)= len G1 by MATRIX_1:def 8,def 9; then 1<=i & i<=width G1 by A39,FINSEQ_3:27; then consider m such that A42: m in dom g & g/.m in rng Col(G1,i) by A9,A10,A11,A12,GOBOARD1:49; A43: dom Col(G1,i) = Seg len G1 by A41,FINSEQ_1:def 3 .= dom G1 by FINSEQ_1:def 3; consider j such that A44: j in dom Ci & g/.m=Ci/.j by A42,PARTFUN2:4; A45: dom Ci = Seg len Ci by FINSEQ_1:def 3; reconsider Lj = Line(G1,j) as FinSequence of TOP-REAL 2; A46: g/.m in rng g by A42,PARTFUN2:4; A47: g1/.n in rng g1 by A38,PARTFUN2:4; len Line(G1,mi) = width G1 by MATRIX_1:def 8 .= len Lj by MATRIX_1:def 8; then A48: dom Line(G1,mi) = dom Lj by A40,FINSEQ_1:def 3; A49: g/.m = Ci.j by A44,FINSEQ_4:def 4 .= Lj.i by A39,A40,A41,A43,A44,GOBOARD1:17 .= Lj/.i by A39,A48,FINSEQ_4:def 4; len Lj=width G1 by MATRIX_1:def 8; then i in dom Lj by A39,A40,A41,FINSEQ_1:def 3; then g/.m in rng Lj by A49,PARTFUN2:4; then A50: rng g /\ rng Line(G1,j) <> {} by A46,XBOOLE_0:def 3; now assume j<>mi; then j<mi or j>mi by REAL_1:def 5; hence contradiction by A25,A26,A27,A37,A41,A44,A45,A50; end; hence thesis by A34,A39,A46,A47,A49,XBOOLE_0:def 3; end; consider k1 be Nat such that A51: k1 in dom Lmi & g1/.ma1 = Lmi/.k1 by A31,PARTFUN2:4; A52: Seg len Lmi = dom Lmi by FINSEQ_1:def 3; reconsider Ck1 = Col(G1,k1) as FinSequence of TOP-REAL 2; 1<=mi & ma<=len G1 by A25,A27,FINSEQ_3:27; then reconsider l1=mi-1, l2=len G1-ma as Nat by INT_1:18; deffunc F(Nat) = G1*($1,k1); consider h1 be FinSequence of TOP-REAL 2 such that A53: len h1 = l1 & for n st n in dom h1 holds h1/.n=F(n) from PiLambdaD; A54: k1 in Seg width G1 by A51,A52,MATRIX_1:def 8; now per cases; suppose A55: k=0; reconsider c1 = Col(G1,1) as FinSequence of TOP-REAL 2; consider x being Nat such that A56: x in dom c1 & g2/.1=c1/.x by A5,PARTFUN2:4; A57: Seg len c1 = dom c1 & dom c1 c= NAT & len c1 = len G1 & dom G1 = Seg len G1 by FINSEQ_1:def 3,MATRIX_1:def 9; reconsider lx = Line(G1,x) as FinSequence of TOP-REAL 2; 0<>width G1 by GOBOARD1:def 5; then 0+1<=width G1 by RLVECT_1:99; then A58: 1 in Seg width G1 & x in dom G1 & Seg len lx=dom lx & len lx=width G1 & Seg len g2=dom g2 by A56,A57,FINSEQ_1:3,def 3,MATRIX_1:def 8; 1<=x & x<=len G1 by A56,A57,FINSEQ_3:27; then consider m such that A59: m in dom g1 & g1/.m in rng lx by A5,GOBOARD1:45; consider y being Nat such that A60: y in dom lx & lx/.y=g1/.m by A59,PARTFUN2:4; A61: lx/.y = lx.y & c1/.x = c1.x by A56,A60,FINSEQ_4:def 4; A62: y=1 & 1 in dom g2 by A5,A55,A58,A60,FINSEQ_1:4,FINSEQ_3:27,TARSKI:def 1 ; then A63: g1/.m=g2/.1 by A56,A58,A60,A61,GOBOARD1:17; A64: g1/.m in rng g1 by A59,PARTFUN2:4; g2/.1 in rng g2 by A62,PARTFUN2:4; hence thesis by A63,A64,XBOOLE_0:def 3; suppose A65: k<>0; then A66: 0<k by NAT_1:19; now per cases; suppose mi=ma; hence thesis by A36; suppose A67: mi<>ma; defpred P[Nat] means $1 in dom g1 & ma1<$1 & g1/.$1 in rng Line(G1,ma); A68: mi<=ma by A25,A27; then A69: mi<ma by A67,REAL_1:def 5; then A70: ex n st P[n] by A5,A25,A28,A31,GOBOARD1:53; consider mi1 be Nat such that A71: P[mi1] & for n st P[n] holds mi1<=n from Min(A70); set f1=g1|mi1; ma1<=mi1 & mi1<=mi1+1 by A71,NAT_1:29; then ma1<=mi1+1 by AXIOMS:22; then reconsider l=mi1+1-ma1 as Nat by INT_1:18; 1<=ma1 by A31,FINSEQ_3:27; then reconsider w=ma1-1 as Nat by INT_1:18; A72: for n st n in Seg l holds f1/.(w+n)=g1/.(w+n) & w+n in dom g1 proof let n such that A73: n in Seg l; 0+1<=ma1 by A31,FINSEQ_3:27; then 0<=ma1-1 & 1<=n & n<=l by A73,FINSEQ_1:3,REAL_1:84; then A74: 0+1<=ma1-1+n & n+ma1<=l+ma1 by REAL_1:55; then n+ma1<=mi1+1 by XCMPLX_1:27; then n+ma1-1<=mi1 by REAL_1:86; then ma1-1+n<=mi1 by XCMPLX_1:29; then w+n in Seg mi1 by A74,FINSEQ_1:3; hence thesis by A71,GOBOARD1:10; end; defpred P[Nat,Element of TOP-REAL 2] means $2=f1/.(w+$1); A75: for n st n in Seg l ex p st P[n,p]; consider f such that A76: len f = l & for n st n in Seg l holds P[n,f/.n] from FinSeqDChoice(A75); A77: dom f = Seg l by A76,FINSEQ_1:def 3; reconsider Lma = Line(G1,ma) as FinSequence of TOP-REAL 2; consider k2 be Nat such that A78: k2 in dom Lma & g1/.mi1=Lma/.k2 by A71,PARTFUN2:4; A79: dom Lma = Seg len Lma by FINSEQ_1:def 3; reconsider Ck2 = Col(G1,k2) as FinSequence of TOP-REAL 2; A80: k2 in Seg width G1 by A78,A79,MATRIX_1:def 8; deffunc F(Nat) = G1*(ma+$1,k2); consider h2 be FinSequence of TOP-REAL 2 such that A81: len h2 = l2 & for n st n in dom h2 holds h2/.n = F(n) from PiLambdaD; A82: dom h2 = Seg len h2 by FINSEQ_1:def 3; set ff = h1^f^h2; ma1+1<=mi1 & mi1<=mi1+1 by A71,NAT_1:38; then A83: ma1+1<=mi1+1 & Seg len f=dom f & Seg len h2=dom h2 & dom h1=Seg len h1 by AXIOMS:22,FINSEQ_1:def 3; then A84: 1<=l & len f=l by A76,REAL_1:84; A85: Indices G1=[:dom G1,Seg width G1:] by MATRIX_1:def 5; A86: now let n; assume n in dom h1; then A87: 1<=n & n<=l1 & l1<=mi & mi<=len G1 by A25,A53,FINSEQ_3:27,PROB_1:2; then n<=mi by AXIOMS:22; then n<=len G1 by A87,AXIOMS:22; hence n in dom G1 by A87,FINSEQ_3:27; end; A88: now let n; assume n in dom h2; then 1<=n & n<=l2 & n<=n+ma by A81,FINSEQ_3:27,NAT_1:29; then 1<=n+ma & ma+n<=ma+l2 by AXIOMS:22,REAL_1:55; then 1<=ma+n & ma+n<=len G1 by XCMPLX_1:27; hence ma+n in dom G1 by FINSEQ_3:27; end; A89: now let n; assume n in dom h1; then A90: h1/.n=G1*(n,k1) & n in dom G1 by A53,A86; take i=n,k1; thus [i,k1] in Indices G1 & h1/.n=G1*(i,k1) by A54,A85,A90,ZFMISC_1:106; end; A91: now let n; assume n in dom h2; then A92: h2/.n=G1*(ma+n,k2) & ma+n in dom G1 by A81,A88; take m=ma+n,k2; thus [m,k2] in Indices G1 & h2/.n=G1*(m,k2) by A80,A85,A92,ZFMISC_1:106; end; A93: now let n; assume n in dom f; then A94: n in Seg l & dom f=Seg l & f/.n=f1/.(w+n) by A76,A77; then w is Nat & w+n in dom g1 & f/.n=g1/.(w+n) by A72; then consider i,j such that A95: [i,j] in Indices G1 & g1/.(w+n)=G1*(i,j) by A5,GOBOARD1:def 11; take i,j; thus [i,j] in Indices G1 & f/.n=G1*(i,j) by A72,A94,A95; end; then for n st n in dom(h1^f) ex i,j st [i,j] in Indices G1 & (h1^f)/.n=G1*(i,j) by A89,GOBOARD1:39; then A96: for n st n in dom ff ex i,j st [i,j] in Indices G1 & ff/.n=G1*(i,j) by A91,GOBOARD1:39; A97: now let n; assume n in dom h1 & n+1 in dom h1; then A98: n in dom G1 & n+1 in dom G1 & h1/.n=G1*(n,k1) & h1/.(n+1)=G1*(n+1,k1) by A53,A86; then A99: [n,k1] in Indices G1 & [n+1,k1] in Indices G1 by A54,A85,ZFMISC_1:106; let i1,i2,j1,j2 be Nat; assume [i1,i2] in Indices G1 & [j1,j2] in Indices G1 & h1/.n=G1*(i1,i2) & h1/.(n+1)=G1*(j1,j2); then i1=n & i2=k1 & j1=n+1 & j2=k1 & 0<=1 by A98,A99,GOBOARD1:21; hence abs(i1-j1)+abs(i2-j2)=abs(n-n-1)+abs(k1-k1) by XCMPLX_1:36 .= abs(n-n-1)+abs(0) by XCMPLX_1:14 .= abs(n-n-1)+0 by ABSVALUE:7 .= abs(n-n+-1)+0 by XCMPLX_0:def 8 .= abs(-1) by XCMPLX_1:25 .= abs(1) by ABSVALUE:17 .= 1 by ABSVALUE:def 1; end; A100: w+l=w+(mi1-ma1+1) by XCMPLX_1:29 .= w+(mi1-(w)) by XCMPLX_1:37 .= mi1 by XCMPLX_1:27; A101: now let n; assume n in dom h2 & n+1 in dom h2; then A102: ma+n in dom G1 & ma+(n+1) in dom G1 & h2/.n=G1*(ma+n,k2) & h2/.(n+1)=G1*(ma+(n+1),k2) & ma+(n+1)=ma+n+1 by A81,A88,XCMPLX_1:1; then A103: [ma+n,k2] in Indices G1 & [ma+n+1,k2] in Indices G1 by A80,A85,ZFMISC_1:106; let i1,i2,j1,j2 be Nat; assume [i1,i2] in Indices G1 & [j1,j2] in Indices G1 & h2/.n=G1* (i1,i2) & h2/.(n+1)=G1*(j1,j2); then i1=ma+n & i2=k2 & j1=ma+n+1 & j2=k2 & 0<=1 by A102,A103, GOBOARD1:21; hence abs(i1-j1)+abs(i2-j2)=abs(ma+n-(ma+n)-1)+abs(k2-k2) by XCMPLX_1:36 .= abs(ma+n-(ma+n)-1)+abs(0) by XCMPLX_1:14 .= abs(ma+n-(ma+n)-1)+0 by ABSVALUE:7 .= abs(ma+n-(ma+n)+-1)+0 by XCMPLX_0:def 8 .= abs(-1) by XCMPLX_1:25 .= abs(1) by ABSVALUE:17 .= 1 by ABSVALUE:def 1; end; A104: now let n; assume n in dom f & n+1 in dom f; then n in Seg l & n+1 in Seg l & dom f=Seg l & f/.n=f1/.(w+n) & f/.(n+1)=f1/.(w+(n+1)) & w+(n+1)=w+n+1 by A76,A77,XCMPLX_1:1; then A105: w is Nat & w+n in dom g1 & f/.n=g1/.(w+n) & w+n+1 in dom g1 & f/.(n+1)=g1/.(w+n+1) by A72; let i1,i2,j1,j2 be Nat; assume [i1,i2] in Indices G1 & [j1,j2] in Indices G1 & f/.n=G1*(i1,i2) & f/.(n+1)=G1*(j1,j2); hence abs(i1-j1)+abs(i2-j2)=1 by A5,A105,GOBOARD1:def 11; end; now let i1,i2,j1,j2 be Nat; assume A106: [i1,i2] in Indices G1 & [j1,j2] in Indices G1 & h1/.len h1=G1*(i1,i2) & f/.1=G1*(j1,j2) & len h1 in dom h1 & 1 in dom f; then A107: h1/.len h1=G1*(l1,k1) & l1 in dom G1 by A53,A86; then [l1,k1] in Indices G1 by A54,A85,ZFMISC_1:106; then A108: i1=l1 & i2=k1 & 0<=1 by A106,A107,GOBOARD1:21; A109: Lmi/.k1 = Lmi.k1 by A51,FINSEQ_4:def 4; A110: w+1=ma1 by XCMPLX_1:27; then 1 in Seg l & dom f=Seg l & f/.1=f1/.ma1 by A76,A77,A106; then A111: f/.1=g1/.ma1 by A72,A110 .= G1*(mi,k1) by A51,A54,A109,MATRIX_1:def 8; [mi,k1] in Indices G1 by A25,A54,A85,ZFMISC_1:106; then j1=mi & j2=k1 by A106,A111,GOBOARD1:21; hence abs(i1-j1)+abs(i2-j2)= abs(mi-1-mi)+abs(0) by A108,XCMPLX_1:14 .= abs(mi-1-mi)+0 by ABSVALUE:7 .= abs(mi+-1-mi) by XCMPLX_0:def 8 .= abs(-1) by XCMPLX_1:26 .= abs(1) by ABSVALUE:17 .= 1 by ABSVALUE:def 1; end; then A112: for n st n in dom(h1^f) & n+1 in dom(h1^f) for i1,i2,j1,j2 be Nat st [i1,i2] in Indices G1 & [j1,j2] in Indices G1 & (h1^f)/.n=G1*(i1,i2) & (h1^f)/.(n+1)=G1*(j1,j2) holds abs(i1-j1)+abs(i2-j2)=1 by A97,A104,GOBOARD1:40; set hf=h1^f; now let i1,i2,j1,j2 be Nat; assume A113: [i1,i2] in Indices G1 & [j1,j2] in Indices G1 & hf/.len hf=G1*(i1,i2) & h2/.1=G1*(j1,j2) & len hf in dom hf & 1 in dom h2; then A114: h2/.1=G1*(ma+1,k2) & ma+1 in dom G1 by A81,A88; then [ma+1,k2] in Indices G1 by A80,A85,ZFMISC_1:106; then A115: j1=ma+1 & j2=k2 by A113,A114,GOBOARD1:21; A116: len f in dom f & 0<=1 by A77,A84,FINSEQ_1:3; A117: Lma/.k2 = Lma.k2 by A78,FINSEQ_4:def 4; A118: hf/.len hf=hf/.(len h1+len f) by FINSEQ_1:35 .= f/.len f by A116,GROUP_5:96 .= f1/.(w+l) by A76,A77,A116 .= g1/.mi1 by A72,A76,A77,A100,A116 .= G1*(ma,k2) by A78,A80,A117,MATRIX_1:def 8; [ma,k2] in Indices G1 by A27,A80,A85,ZFMISC_1:106; then i1=ma & i2=k2 by A113,A118,GOBOARD1:21; hence abs(i1-j1)+abs(i2-j2)=abs(ma-(ma+1))+abs(0) by A115,XCMPLX_1:14 .=abs(ma-(ma+1))+0 by ABSVALUE:7 .=abs(-(ma+1 -ma)) by XCMPLX_1:143 .=abs(ma+1 -ma) by ABSVALUE:17 .=abs(1) by XCMPLX_1:26 .=1 by ABSVALUE:def 1; end; then for n st n in dom ff & n+1 in dom ff for m,k,i,j st [m,k] in Indices G1 & [i,j] in Indices G1 & ff/.n=G1*(m,k) & ff/.(n+1)=G1*(i,j) holds abs(m-i)+abs(k-j)=1 by A101,A112,GOBOARD1:40; then A119: ff is_sequence_on G1 by A96,GOBOARD1:def 11; A120: now per cases; suppose A121: mi=1; then h1 = {} by A53,FINSEQ_1:25; then A122: ff=f^h2 by FINSEQ_1:47; A123: 1 in Seg l & 1<=ma1 by A6,A31,A84,FINSEQ_1:3; then A124: ma1 in Seg mi1 by A71,FINSEQ_1:3; A125: w+1=ma1 by XCMPLX_1:27; ff/.1=f/.1 by A77,A122,A123,GROUP_5:95 .= f1/.ma1 by A76,A123,A125 .= g1/.ma1 by A71,A124,GOBOARD1:10; hence ff/.1 in rng Line(G1,1) by A31,A121; suppose A126: mi<>1; 1<=mi by A25,FINSEQ_3:27; then 1<mi by A126,REAL_1:def 5; then 1+1<=mi by NAT_1:38; then A127: 1<=l1 by REAL_1:84; then A128: 1 in dom h1 by A53,FINSEQ_3:27; A129: len(h1^f)=len h1 + len f by FINSEQ_1:35; A130: len Line(G1,1)=width G1 by MATRIX_1:def 8; then dom Line(G1,1) = Seg width G1 by FINSEQ_1:def 3; then A131: L1/.k1 = L1.k1 by A54,FINSEQ_4:def 4; 0<=len f by NAT_1:18; then 0+1<=len(h1^f) by A53,A127,A129,REAL_1:55; then 1 in dom(h1^f) by FINSEQ_3:27; then A132: ff/.1=(h1^f)/.1 by GROUP_5:95 .=h1/.1 by A128,GROUP_5:95 .=G1*(1,k1) by A53,A128 .=L1/.k1 by A54,A131,MATRIX_1:def 8; k1 in dom L1 by A54,A130,FINSEQ_1:def 3; hence ff/.1 in rng Line(G1,1) by A132,PARTFUN2:4; end; A133: len ff=len(h1^f)+len h2 by FINSEQ_1:35 .=len h1+len f+len h2 by FINSEQ_1:35; 0+0<=len h1+len h2 by NAT_1:18; then 0+1<=len f+(len h1+len h2) by A84,REAL_1:55; then A134: 1<=len ff by A133,XCMPLX_1:1; A135: now per cases; suppose A136: ma=len G1; then l2=0 & g1/.mi1 in rng Line(G1,len G1) by A71,XCMPLX_1:14; then h2 = {} by A81,FINSEQ_1:25; then A137: ff=h1^f & 1<=mi1 by A71,FINSEQ_1:47,FINSEQ_3:27; then A138: len f in dom f & mi1 in Seg mi1 by A83,A84,FINSEQ_1:3; ff/.len ff=ff/.(len h1+len f) by A137,FINSEQ_1:35 .= f/.l by A76,A137,A138,GROUP_5:96 .= f1/.mi1 by A76,A77,A100,A138 .= g1/.mi1 by A71,A138,GOBOARD1:10; hence ff/.len ff in rng Line(G1,len G1) by A71,A136; suppose A139: ma<>len G1; ma<=len G1 by A27,FINSEQ_3:27; then ma<len G1 by A139,REAL_1:def 5; then ma+1<=len G1 by NAT_1:38; then A140: 1<=l2 by REAL_1:84; then A141: l2 in Seg l2 by FINSEQ_1:3; A142: len h2 in dom h2 by A81,A140,FINSEQ_3:27; A143: len Line(G1,len G1)=width G1 by MATRIX_1:def 8; then k2 in dom Ll by A80,FINSEQ_1:def 3; then A144: Ll/.k2 = Ll.k2 by FINSEQ_4:def 4; A145: ff/.len ff=ff/.(len(h1^f)+len h2) by FINSEQ_1:35 .=h2/.l2 by A81,A142,GROUP_5:96 .=G1*(ma+l2,k2) by A81,A82,A141 .=G1*(len G1,k2) by XCMPLX_1:27 .=Ll/.k2 by A80,A144,MATRIX_1:def 8; k2 in dom Ll by A80,A143,FINSEQ_1:def 3; hence ff/.len ff in rng Line(G1,len G1) by A145,PARTFUN2:4; end; A146: rng ff = rng(h1^f) \/ rng h2 by FINSEQ_1:44 .= rng h1 \/ rng f \/ rng h2 by FINSEQ_1:44; A147: for k st k in Seg width G1 & rng f /\ rng Col(G1,k)={} holds rng ff /\ rng Col(G1,k)={} proof let k; assume that A148: k in Seg width G1 and A149: rng f /\ rng Col(G1,k)={}; set gg=Col(G1,k); assume A150: rng ff /\ rng gg <> {}; consider x being Element of rng ff /\ rng gg; A151: w+1=ma1 by XCMPLX_1:27; rng ff = rng f \/ (rng h1 \/ rng h2) by A146,XBOOLE_1:4; then A152: rng ff /\ rng gg = {} \/ (rng h1 \/ rng h2) /\ rng gg by A149,XBOOLE_1:23 .= rng h1 /\ rng gg \/ rng h2 /\ rng gg by XBOOLE_1:23; A153: len Col(G1,k1)=len G1 & len Col(G1,k2)=len G1 by MATRIX_1:def 9; now per cases by A150,A152,XBOOLE_0:def 2; suppose x in rng h1 /\ rng gg; then A154: x in rng h1 & x in rng gg by XBOOLE_0:def 3; then consider i such that A155: i in dom h1 & x=h1/.i by PARTFUN2:4; A156: x=G1*(i,k1) by A53,A155; reconsider y=x as Point of TOP-REAL 2 by A155; A157: dom Col(G1,k1) = Seg len G1 by A153,FINSEQ_1:def 3 .= dom G1 by FINSEQ_1:def 3; then A158: i in dom Ck1 by A86,A155; A159: Lmi/.k1 = Lmi.k1 & Ck1/.mi = Ck1.mi by A25,A51,A157,FINSEQ_4:def 4; Ck1/.i = Ck1.i by A158,FINSEQ_4:def 4; then y=Ck1/.i by A156,A157,A158,MATRIX_1:def 9; then y in rng Ck1 by A158,PARTFUN2:4; then A160: k1=k & 1 in Seg l by A54,A84,A148,A154,FINSEQ_1:3,GOBOARD1:20; then f/.1=f1/.ma1 & f1/.ma1=g1/.(w+1) by A72,A76,A151; then f/.1=Lmi/.k1 by A51,XCMPLX_1:27 .= Ck1/.mi by A25,A54,A159,GOBOARD1:17; then f/.1 in rng Col(G1,k) & f/.1 in rng f by A25,A77,A157,A160,PARTFUN2:4; hence contradiction by A149,XBOOLE_0:def 3; suppose x in rng h2 /\ rng gg; then A161: x in rng h2 & x in rng gg by XBOOLE_0:def 3; then consider i such that A162: i in dom h2 & x=h2/.i by PARTFUN2:4; A163: x=G1*(ma+i,k2) by A81,A162; reconsider y=x as Point of TOP-REAL 2 by A162; A164: dom Col(G1,k2) = Seg len G1 by A153,FINSEQ_1:def 3 .= dom G1 by FINSEQ_1:def 3; then A165: ma+i in dom Ck2 by A88,A162; A166: Lma/.k2 = Lma.k2 & Ck2/.ma = Ck2.ma by A27,A78,A164,FINSEQ_4:def 4; Ck2/.(ma+i) = Ck2.(ma+i) by A165,FINSEQ_4:def 4; then y=Ck2/.(ma+i) by A163,A164,A165,MATRIX_1:def 9; then y in rng Ck2 by A165,PARTFUN2:4; then A167: k2=k & l in Seg l by A80,A84,A148,A161,FINSEQ_1:3, GOBOARD1:20 ; then f/.l=f1/.(w+l) & f1/.(w+l)=g1/.(w+l) by A72,A76; then f/.l=Ck2/.ma by A27,A78,A80,A100,A166,GOBOARD1:17; then f/.l in rng Col(G1,k) & f/.l in rng f by A27,A77,A164,A167,PARTFUN2:4; hence contradiction by A149,XBOOLE_0:def 3; end; hence contradiction; end; A168: rng h1 /\ rng g = {} proof assume A169: not thesis; consider x being Element of rng h1 /\ rng g; A170: x in rng h1 & x in rng g by A169,XBOOLE_0:def 3; then consider n1 be Nat such that A171: n1 in dom h1 & x=h1/.n1 by PARTFUN2:4; A172: x=G1*(n1,k1) & 1<=n1 & n1<=l1 by A53,A171,FINSEQ_3:27; consider n2 be Nat such that A173: n2 in dom g & x=g/.n2 by A170,PARTFUN2:4; consider i1,i2 be Nat such that A174: [i1,i2] in Indices G1 & g/.n2=G1*(i1,i2) by A10,A173,GOBOARD1:def 11; reconsider L=Line(G1,i1) as FinSequence of TOP-REAL 2; A175: Seg len L = dom L by FINSEQ_1:def 3; A176: i1 in dom G1 & i2 in Seg width G1 by A85,A174,ZFMISC_1:106; A177: len L=width G1 by MATRIX_1:def 8; then L/.i2 = L.i2 by A175,A176,FINSEQ_4:def 4; then g/.n2=L/.i2 by A174,A176,MATRIX_1:def 8; then g/.n2 in rng L & g/.n2 in rng g by A173,A175,A176,A177,PARTFUN2:4; then rng g /\ rng L <> {} by XBOOLE_0:def 3; then A178: mi<=i1 by A25,A176; n1 in dom G1 by A86,A171; then [n1,k1] in Indices G1 by A54,A85,ZFMISC_1:106; then i1=n1 & 0<1 by A172,A173,A174,GOBOARD1:21; then mi<=mi-1 & mi-1<mi by A172,A178,AXIOMS:22,SQUARE_1:29; hence contradiction; end; rng h2 /\ rng g = {} proof assume A179: not thesis; consider x being Element of rng h2 /\ rng g; A180: x in rng h2 & x in rng g by A179,XBOOLE_0:def 3; then consider n1 be Nat such that A181: n1 in dom h2 & x=h2/.n1 by PARTFUN2:4; A182: x=G1*(ma+n1,k2) & 1<=n1 & n1<=l2 by A81,A181,FINSEQ_3:27; consider n2 be Nat such that A183: n2 in dom g & x=g/.n2 by A180,PARTFUN2:4; consider i1,i2 be Nat such that A184: [i1,i2] in Indices G1 & g/.n2=G1*(i1,i2) by A10,A183,GOBOARD1:def 11; reconsider L=Line(G1,i1) as FinSequence of TOP-REAL 2; A185: Seg len L = dom L by FINSEQ_1:def 3; A186: i1 in dom G1 & i2 in Seg width G1 by A85,A184,ZFMISC_1:106; A187: len L=width G1 by MATRIX_1:def 8; then L/.i2 = L.i2 by A185,A186,FINSEQ_4:def 4; then g/.n2=L/.i2 by A184,A186,MATRIX_1:def 8; then g/.n2 in rng L & g/.n2 in rng g by A183,A185,A186,A187,PARTFUN2:4; then rng g /\ rng L <> {} by XBOOLE_0:def 3; then A188: i1<=ma by A27,A186; ma+n1 in dom G1 by A88,A181; then [ma+n1,k2] in Indices G1 by A80,A85,ZFMISC_1:106; then i1=ma+n1 by A182,A183,A184,GOBOARD1:21; then n1<=0 by A188,REAL_2:174; hence contradiction by A182,AXIOMS:22; end; then A189: rng ff /\ rng g = ((rng h1 \/ rng f) /\ rng g) \/ {} by A146,XBOOLE_1:23 .= {} \/ rng f /\ rng g by A168,XBOOLE_1:23 .= rng f /\ rng g; A190: rng f c= rng g1 proof let x; assume x in rng f; then consider n such that A191: n in dom f & x=f/.n by PARTFUN2:4; n in Seg l & n in Seg l & f/.n=f1/.(w+n) by A76,A83,A191; then w is Nat & w+n in dom g1 & f/.n=g1/.(w+n) by A72; hence x in rng g1 by A191,PARTFUN2:4; end; then A192: rng ff /\ rng g c= rng g1 /\ rng g2 by A34,A189,XBOOLE_1:27; A193: 0+1<width G1 by A5,A66,REAL_1:53; then A194: len DelCol(G1,1)=len G1 & len DelCol(G1,width G1)=len G1 & Seg len ff=dom ff by A14,A15,FINSEQ_1:def 3,GOBOARD1:def 10; then A195: 1 in dom ff & len ff in dom ff by A134,FINSEQ_1:3; A196: dom DelCol(G1,1) = Seg len G1 by A194,FINSEQ_1:def 3 .= dom G1 by FINSEQ_1:def 3; thus thesis proof per cases; suppose rng f /\ rng Col(G1,1)={}; then rng ff /\ rng Col(G1,1)={} by A14,A147; then A197: rng ff misses rng Col(G1,1) by XBOOLE_0:def 7; defpred P[Nat] means $1 in dom g & g/.$1 in rng Col(G1,1); A198: for m st P[m] holds m<=len g by FINSEQ_3:27; A199: ex m st P[m] proof take 1; thus thesis by A5,A8,A9,FINSEQ_3:27,GOBOARD1:22; end; consider m such that A200: P[m] & for k st P[k] holds k<=m from Max(A198,A199); reconsider p=g/.m as Point of TOP-REAL 2; A201: now assume A202: m>=len g; m<=len g by A200,FINSEQ_3:27; then p in rng Col(G1,1) & p in rng Col(G1,width G1) by A12,A200,A202,AXIOMS:21; then 1=k+1 by A5,A14,A15,GOBOARD1:20; hence contradiction by A65,XCMPLX_1:3; end; then reconsider ll = len g-m as Nat by INT_1:18; deffunc F(Nat) = g/.(m+$1); consider t be FinSequence of TOP-REAL 2 such that A203: len t = ll & for n st n in dom t holds t/.n = F(n) from PiLambdaD; A204: Seg len t = dom t by FINSEQ_1:def 3; A205: dom t = Seg ll by A203,FINSEQ_1:def 3; A206: for n st n in dom t holds m+n in dom g proof let n; assume n in dom t; then 1<=n & n<=ll & n<=n+m by A205,FINSEQ_1:3,NAT_1:29; then 1<=n+m & m+n<=m+ll by AXIOMS:22,REAL_1:55; then 1<=m+n & m+n<=len g by XCMPLX_1:27; hence thesis by FINSEQ_3:27; end; A207: rng t c= rng g proof let y; assume y in rng t; then consider x being Nat such that A208: x in dom t & t/.x=y by PARTFUN2:4; 1<=x & x<=ll & x<=x+m by A205,A208,FINSEQ_1:3,NAT_1:29; then 1<=x+m & m+x<=m+ll by AXIOMS:22,REAL_1:55; then 1<=m+x & m+x<=len g by XCMPLX_1:27; then m+x in dom g by FINSEQ_3:27; then g/.(m+x) in rng g by PARTFUN2:4; hence thesis by A203,A208; end; reconsider t as FinSequence of TOP-REAL 2; set D = DelCol(G1,1); A209: width D = k by A5,A14,A66,GOBOARD1:26; 0<>width D by GOBOARD1:def 5; then 0<width D by NAT_1:19; then A210: 0+1<=width D by NAT_1:38; m+1<=len g by A201,NAT_1:38; then A211: 1<=len t by A203,REAL_1:84; then 1 in Seg ll by A203,FINSEQ_1:3; then A212: t/.1 = g/.(m+1) by A203,A204; Col(D,1)=Col(G1,1+1) & 1+1 in Seg width G1 by A5,A14,A66,A209,A210,GOBOARD1:30; then A213: t/.1 in rng Col(D,1) by A9,A10,A12,A14,A200,A212,GOBOARD1:48; len t in Seg ll by A203,A211,FINSEQ_1:3; then t/.len t = g/.(m+ll) by A203,A204 .= g/.len g by XCMPLX_1:27; then A214: t/.len t in rng Col(D,width D) by A5,A12,A14,A66,A209,A210,GOBOARD1:30; A215: Indices D = [:dom D,Seg width D:] by MATRIX_1:def 5; A216: now let n; assume A217: n in dom t; then m+n in dom g by A206; then consider i1,i2 be Nat such that A218: [i1,i2] in Indices G1 & g/.(m+n)=G1*(i1,i2) by A10,GOBOARD1:def 11; take i1; reconsider Ci2 = Col(G1,i2) as FinSequence of TOP-REAL 2; A219: i1 in dom G1 & i2 in Seg width G1 & t/.n=g/.(m+n) & m+n in dom g by A85,A203,A206,A217,A218,ZFMISC_1:106; len Ci2 = len G1 by MATRIX_1:def 9; then A220: dom Ci2 = Seg len G1 by FINSEQ_1:def 3 .= dom G1 by FINSEQ_1:def 3; then Ci2/.i1 = Ci2.i1 by A219,FINSEQ_4:def 4; then Ci2/.i1 = G1*(i1,i2) & dom Col(G1,i2)=dom Col(G1,i2) & len Col(G1,i2)=len G1 by A219,MATRIX_1:def 9; then A221: g/.(m+n) in rng Col(G1,i2) by A218,A219,A220,PARTFUN2:4; now assume i2=1; then A222: m+n<=m & 1<=n by A200,A205,A217,A219,A221,FINSEQ_1:3; then m+1<=m+n by REAL_1:55; then m+1<=m by A222,AXIOMS:22; then 1<=m-m by REAL_1:84; then 1<=0 by XCMPLX_1:14; hence contradiction; end; then A223: 1<>i2 & 1<=i2 & i2<=width G1 by A219,FINSEQ_1:3; then A224: 1<i2 by REAL_1:def 5; reconsider l=i2-1 as Nat by A223,INT_1:18; take l; 1+1<=i2 by A224,NAT_1:38; then A225: 1<=l & l<=width D & l+1=i2 by A5,A209,A223,REAL_1:84,86, XCMPLX_1:27; then l in Seg width D by FINSEQ_1:3; hence [i1,l] in Indices D by A196,A215,A219,ZFMISC_1:106; thus t/.n = D*(i1,l) by A5,A14,A66,A209,A218,A219,A225,GOBOARD1:32; end; now let n; assume A226: n in dom t & n+1 in dom t; then A227: t/.n=g/.(m+n) & t/.(n+1)=g/.(m+(n+1)) by A203; let i1,i2,j1,j2 be Nat; assume A228: [i1,i2] in Indices D & [j1,j2] in Indices D & t/.n=D*(i1,i2) & t/.(n+1)=D*(j1,j2); then A229: i1 in dom D & i2 in Seg k & j1 in dom D & j2 in Seg k & m+(n+1)=m+n+1 by A209,A215,XCMPLX_1:1,ZFMISC_1:106; then 1<=i2 & i2<=k & 1<=j2 & j2<=k by FINSEQ_1:3; then A230: g/.(m+n)=G1*(i1,i2+1) & g/.(m+n+1)=G1*(j1,j2+1) & i2+1 in Seg width G1 & j2+1 in Seg width G1 by A5,A14,A66,A196,A227,A228,A229,GOBOARD1:32; then A231: [i1,i2+1] in Indices G1 & [j1,j2+1] in Indices G1 by A85,A196,A229,ZFMISC_1:106; m+n in dom g & m+n+1 in dom g by A206,A226,A229; hence 1= abs(i1-j1)+abs(i2+1 -(j2+1)) by A10,A230,A231,GOBOARD1:def 11 .=abs(i1-j1)+abs(i2-j2) by XCMPLX_1:32; end; then A232: t is_sequence_on D by A216,GOBOARD1:def 11; ff is_sequence_on D & ff/.1 in rng Line(D,1) & ff/.len ff in rng Line(D,len D) by A14,A16,A17,A119,A120,A135,A193,A194,A195,A197,GOBOARD1:37,41; then A233:rng ff /\ rng t <> {} by A4,A66,A134,A209,A211,A213,A214,A232; consider x being Element of rng ff /\ rng t; rng ff /\ rng t c= rng ff /\ rng g by A207,XBOOLE_1:26; then x in rng ff /\ rng g by A233,TARSKI:def 3; hence thesis by A192; suppose A234: rng f /\ rng Col(G1,1) <> {}; set D = DelCol(G1,width G1); A235: 0+1<k+1 by A66,REAL_1:53; now per cases; suppose rng f /\ rng Col(G1,width G1) = {}; then rng ff /\ rng Col(G1,width G1) = {} by A15,A147; then A236: rng ff misses rng Col(G1,width G1) by XBOOLE_0:def 7; consider t be FinSequence of TOP-REAL 2 such that A237: t/.1 in rng Col(D,1) & t/.len t in rng Col(D,width D) & 1<=len t & t is_sequence_on D & rng t c= rng g by A5,A9,A10,A11,A12,A235,GOBOARD1:51; A238: width D = k by A5,A15,A66,GOBOARD1:26; ff/.1 in rng Line(D,1) & ff/.len ff in rng Line(D,len D) & ff is_sequence_on D by A15,A16,A17,A119,A120,A135,A193,A194,A195,A236,GOBOARD1:37,41; then A239: rng ff /\ rng t <> {} by A4,A66,A134,A237,A238; consider x being Element of rng ff /\ rng t; rng ff /\ rng t c= rng ff /\ rng g by A237,XBOOLE_1:26; then x in rng ff /\ rng g by A239,TARSKI:def 3; hence thesis by A192; suppose A240: rng f /\ rng Col(G1,width G1) <> {}; A241: f is_sequence_on G1 by A93,A104,GOBOARD1:def 11; then consider t be FinSequence of TOP-REAL 2 such that A242: rng t c= rng f & t/.1 in rng Col(G1,1) & t/.len t in rng Col(G1,width G1) & 1<=len t & t is_sequence_on G1 by A234,A240,GOBOARD1:52; consider tt be FinSequence of TOP-REAL 2 such that A243: tt/.1 in rng Col(D,1) & tt/.len tt in rng Col(D,width D) & 1<=len tt & tt is_sequence_on D & rng tt c= rng t by A5,A235,A242,GOBOARD1:51; defpred P[Nat] means $1 in dom g & g/.$1 in rng Line(G1,mi); A244: now consider x being Element of rng g /\ rng Line(G1,mi); x in rng g & x in rng Line(G1,mi) by A25,XBOOLE_0:def 3; then consider n such that A245: n in dom g & x=g/.n by PARTFUN2:4; take n; thus P[n] by A25,A245,XBOOLE_0:def 3; end; defpred R[Nat] means $1 in dom g & g/.$1 in rng Line(G1,ma); A246: now consider x being Element of rng g /\ rng Line(G1,ma); x in rng g & x in rng Line(G1,ma) by A27,XBOOLE_0:def 3; then consider n such that A247: n in dom g & x=g/.n by PARTFUN2:4; take n; thus R[n] by A27,A247,XBOOLE_0:def 3; end; consider pf be Nat such that A248: P[pf] & for n st P[n] holds pf<=n from Min(A244); consider pl be Nat such that A249: R[pl] & for n st R[n] holds pl<=n from Min(A246); A250: pl <> pf by A25,A27,A67,A248,A249,GOBOARD1:19; A251: 1<=pf & pf<=len g & 1<=pl & pl<=len g by A248,A249,FINSEQ_3:27; now per cases by A250,REAL_1:def 5; suppose pf<pl; then pf<len g by A251,AXIOMS:22; then 1<len g by A251,AXIOMS:22; hence 1+1<=len g by NAT_1:38; suppose pf>pl; then pl<len g by A251,AXIOMS:22; then 1<len g by A251,AXIOMS:22; hence 1+1<=len g by NAT_1:38; end; then A252: 1<=len g - 1 & 1<=len g by A8,GOBOARD1:38,REAL_1:84; reconsider lg=len g-1 as Nat by A9,INT_1:18; lg<=len g by PROB_1:2; then A253: lg in dom g & len g in dom g & lg+1=len g by A252,FINSEQ_3:27,XCMPLX_1:27; reconsider C = Col(G1,width G1), Li= Line(G1,mi), La= Line(G1,ma) as FinSequence of TOP-REAL 2; A254: dom g c= dom g2 by A6,A19,A32,A33,FINSEQ_1:7; len C=len G1 by MATRIX_1:def 9; then A255: dom C = Seg len G1 by FINSEQ_1:def 3 .= dom G1 by FINSEQ_1:def 3; consider K1 be Nat such that A256: K1 in dom Li & g/.pf=Li/.K1 by A248,PARTFUN2:4; A257: Seg len Li = dom Li by FINSEQ_1:def 3; reconsider CK1 = Col(G1,K1) as FinSequence of TOP-REAL 2; A258: len Li=width G1 by MATRIX_1:def 8; Li/.K1 = Li.K1 by A256,FINSEQ_4:def 4; then A259: K1 in Seg width G1 & g/.pf=G1*(mi,K1) by A256,A257,A258,MATRIX_1:def 8; now assume A260: pf=len g; consider i2 be Nat such that A261: i2 in dom C & C/.i2=g/.len g by A12,PARTFUN2:4; C/.i2 = C.i2 by A261,FINSEQ_4:def 4; then A262: i2 in dom G1 & g/.len g=G1*(i2,width G1) by A255,A261,MATRIX_1:def 9; A263: [i2,width G1] in Indices G1 by A15,A85,A255,A261,ZFMISC_1:106; [mi,K1] in Indices G1 by A25,A85,A256,A257,A258,ZFMISC_1:106; then A264: i2=mi & width G1=K1 by A259,A260,A262,A263,GOBOARD1:21; consider n1,n2 be Nat such that A265: [n1,n2] in Indices G1 & g/.lg=G1*(n1,n2) by A10,A253,GOBOARD1:def 11; A266: abs(n1-mi)+abs(n2- width G1)=1 by A10,A253,A262,A263,A264,A265,GOBOARD1:def 11; A267: n1 in dom G1 & n2 in Seg width G1 by A85,A265,ZFMISC_1:106; now per cases by A266,GOBOARD1:2; suppose A268: abs(n1-mi)=1 & n2=width G1; A269: dom C = Seg len C by FINSEQ_1:def 3 .= Seg len G1 by MATRIX_1:def 9 .= dom G1 by FINSEQ_1:def 3; then C/.n1 = C.n1 by A267,FINSEQ_4:def 4; then g/.lg=C/.n1 by A265,A267,A268,MATRIX_1:def 9; then g/.lg in rng C & 0<1 & g/.lg=g2/.lg by A8,A19,A33,A253,A267,A269,GOBOARD1:10,PARTFUN2:4; then len g<=lg & lg<len g by A8,A33,A253,A254,SQUARE_1:29; hence contradiction; suppose A270: abs(n2-width G1)=1 & n1=mi; len Li = width G1 by MATRIX_1:def 8; then A271: n2 in dom Li by A267,FINSEQ_1:def 3; then Li/.n2 = Li.n2 by FINSEQ_4:def 4; then g/.lg=Li/.n2 by A265,A267,A270,MATRIX_1:def 8; then g/.lg in rng Li & 0<1 by A271,PARTFUN2:4; then len g<=lg & lg<len g by A248,A253,A260,SQUARE_1:29; hence contradiction; end; hence contradiction; end; then A272: pf<len g by A251,REAL_1:def 5; consider K2 be Nat such that A273: K2 in dom Lma & g/.pl=Lma/.K2 by A249,PARTFUN2:4; A274: Seg len Lma = dom Lma by FINSEQ_1:def 3; reconsider CK2 = Col(G1,K2) as FinSequence of TOP-REAL 2; A275: len Lma=width G1 by MATRIX_1:def 8; Lma/.K2 = Lma.K2 by A273,FINSEQ_4:def 4; then A276: K2 in Seg width G1 & g/.pl=G1*(ma,K2) by A273,A274,A275,MATRIX_1:def 8; now assume A277: pl=len g; consider i2 be Nat such that A278: i2 in dom C & C/.i2=g/.len g by A12,PARTFUN2:4; A279: dom C = Seg len C by FINSEQ_1:def 3 .= Seg len G1 by MATRIX_1:def 9 .= dom G1 by FINSEQ_1:def 3; C/.i2 = C.i2 by A278,FINSEQ_4:def 4; then A280: i2 in dom G1 & g/.len g=G1*(i2,width G1) by A278,A279,MATRIX_1:def 9; A281: [i2,width G1] in Indices G1 by A15,A85,A278,A279,ZFMISC_1:106; [ma,K2] in Indices G1 by A27,A85,A273,A274,A275,ZFMISC_1:106; then A282: i2=ma & width G1=K2 by A276,A277,A280,A281,GOBOARD1:21; consider n1,n2 be Nat such that A283: [n1,n2] in Indices G1 & g/.lg=G1*(n1,n2) by A10,A253,GOBOARD1:def 11; A284: abs(n1-ma)+abs(n2- width G1)=1 by A10,A253,A280,A281,A282,A283,GOBOARD1:def 11; A285: n1 in dom G1 & n2 in Seg width G1 by A85,A283,ZFMISC_1:106; now per cases by A284,GOBOARD1:2; suppose A286: abs(n1-ma)=1 & n2=width G1; A287: dom C = Seg len C by FINSEQ_1:def 3 .= Seg len G1 by MATRIX_1:def 9 .= dom G1 by FINSEQ_1:def 3; then C/.n1 = C.n1 by A285,FINSEQ_4:def 4; then g/.lg=C/.n1 by A283,A285,A286,MATRIX_1:def 9; then g/.lg in rng C & 0<1 & g/.lg=g2/.lg by A8,A19,A33,A253,A285,A287,GOBOARD1:10,PARTFUN2:4; then len g<=lg & lg<len g by A8,A33,A253,A254,SQUARE_1:29; hence contradiction; suppose A288: abs(n2-width G1)=1 & n1=ma; len Lma = width G1 by MATRIX_1:def 8; then A289: n2 in dom Lma by A285,FINSEQ_1:def 3; then La/.n2 = Lma.n2 by FINSEQ_4:def 4; then g/.lg=Lma/.n2 by A283,A285,A288,MATRIX_1:def 8; then g/.lg in rng Lma & 0<1 by A289,PARTFUN2:4; then len g<=lg & lg<len g by A249,A253,A277,SQUARE_1:29; hence contradiction; end; hence contradiction; end; then A290: pl<len g by A251,REAL_1:def 5; deffunc F(Nat) = G1*($1,K1); consider h1 be FinSequence of TOP-REAL 2 such that A291: len h1 = l1 & for n st n in dom h1 holds h1/.n=F(n) from PiLambdaD; A292: Seg len h1 = dom h1 by FINSEQ_1:def 3; deffunc F(Nat) = G1*(ma+$1,K2); consider h2 be FinSequence of TOP-REAL 2 such that A293: len h2=l2 & for n st n in dom h2 holds h2/.n=F(n) from PiLambdaD; A294: Seg len h2 = dom h2 by FINSEQ_1:def 3; A295: now let n; assume n in dom h1; then A296: 1<=n & n<=l1 & l1<=mi & mi<=len G1 by A25,A291,FINSEQ_3:27,PROB_1:2; then n<=mi by AXIOMS:22; then n<=len G1 by A296,AXIOMS:22; hence n in dom G1 by A296,FINSEQ_3:27; end; A297: now let n; assume n in dom h2; then 1<=n & n<=l2 & n<=n+ma by A293,FINSEQ_3:27,NAT_1:29; then 1<=n+ma & ma+n<=ma+l2 by AXIOMS:22,REAL_1:55; then 1<=ma+n & ma+n<=len G1 by XCMPLX_1:27; hence ma+n in dom G1 by FINSEQ_3:27; end; A298: now let n; assume n in dom h1; then A299: h1/.n=G1*(n,K1) & n in dom G1 by A291,A295; take i=n,K1; thus [i,K1] in Indices G1 & h1/.n=G1*(i,K1) by A85,A256,A257,A258,A299,ZFMISC_1:106; end; A300: now let n; assume n in dom h2; then A301: h2/.n=G1*(ma+n,K2) & ma+n in dom G1 by A293,A297; take m=ma+n,K2; thus [m,K2] in Indices G1 & h2/.n=G1*(m,K2) by A85,A273,A274,A275,A301,ZFMISC_1:106; end; A302: now let n; assume n in dom h1 & n+1 in dom h1; then A303: n in dom G1 & n+1 in dom G1 & h1/.n=G1*(n,K1) & h1/.(n+1)=G1*(n+1,K1) by A291,A295; then A304: [n,K1] in Indices G1 & [n+1,K1] in Indices G1 by A85,A256,A257,A258,ZFMISC_1:106; let i1,i2,j1,j2 be Nat; assume [i1,i2] in Indices G1 & [j1,j2] in Indices G1 & h1/.n=G1*(i1,i2) & h1/.(n+1)=G1*(j1,j2); then i1=n & i2=K1 & j1=n+1 & j2=K1 & 0<=1 by A303,A304,GOBOARD1:21; hence abs(i1-j1)+abs(i2-j2)=abs(n-n-1)+abs(K1-K1) by XCMPLX_1:36 .= abs(n-n-1)+abs(0) by XCMPLX_1:14 .= abs(n-n-1)+0 by ABSVALUE:7 .= abs(n-n+-1)+0 by XCMPLX_0:def 8 .= abs(-1) by XCMPLX_1:25 .= abs(1) by ABSVALUE:17 .= 1 by ABSVALUE:def 1; end; A305: now let n; assume n in dom h2 & n+1 in dom h2; then A306: ma+n in dom G1 & ma+(n+1) in dom G1 & h2/.n=G1*(ma+n,K2) & h2/.(n+1)=G1*(ma+(n+1),K2) & ma+(n+1)=ma+n+1 by A293,A297,XCMPLX_1:1; then A307: [ma+n,K2] in Indices G1 & [ma+n+1,K2] in Indices G1 by A85,A273,A274,A275,ZFMISC_1:106; let i1,i2,j1,j2 be Nat; assume [i1,i2] in Indices G1 & [j1,j2] in Indices G1 & h2/.n=G1*(i1,i2) & h2/.(n+1)=G1*(j1,j2); then i1=ma+n & i2=K2 & j1=ma+n+1 & j2=K2 & 0<=1 by A306,A307,GOBOARD1: 21; hence abs(i1-j1)+abs(i2-j2)=abs(ma+n-(ma+n)-1)+abs(K2-K2) by XCMPLX_1:36 .= abs(ma+n-(ma+n)-1)+abs(0) by XCMPLX_1:14 .= abs(ma+n-(ma+n)-1)+0 by ABSVALUE:7 .= abs(ma+n-(ma+n)+-1)+0 by XCMPLX_0:def 8 .= abs(-1) by XCMPLX_1:25 .= abs(1) by ABSVALUE:17 .= 1 by ABSVALUE:def 1; end; defpred PP[Nat] means $1 in dom f implies for m st m in dom G1 & f/.$1 in rng Line(G1,m) holds mi<=m; A308: PP[0] by FINSEQ_3:27; A309: for k st PP[k] holds PP[k+1] proof let k such that A310: PP[k]; assume A311: k+1 in dom f; let m such that A312: m in dom G1 & f/.(k+1) in rng Line(G1,m); now per cases; suppose A313: k=0; A314: w+1=ma1 by XCMPLX_1:27; 1 in Seg l by A84,FINSEQ_1:3; then f/.1=f1/.ma1 & f1/.ma1=g1/.ma1 by A72,A76,A314; then f/.(k+1) in rng Li by A51,A313,PARTFUN2:4; hence mi<=m by A25,A312,GOBOARD1:19; suppose k<>0; then 0<k & k<=k+1 & k+1<=len f by A311,FINSEQ_3:27,NAT_1:19,29; then A315: 0+1<=k & k<=len f by NAT_1:38; then A316: k in dom f by FINSEQ_3:27; then consider i1,i2 be Nat such that A317: [i1,i2] in Indices G1 & f/.k=G1*(i1,i2) by A93; reconsider Li1 = Line(G1,i1) as FinSequence of TOP-REAL 2; A318: Seg len Li1 = dom Li1 by FINSEQ_1:def 3; A319: i1 in dom G1 & i2 in Seg width G1 by A85,A317,ZFMISC_1:106; A320: len Li1=width G1 by MATRIX_1:def 8; then A321: Li1/.i2 = Li1.i2 by A318,A319,FINSEQ_4:def 4; then f/.k=Li1/.i2 by A317,A319,MATRIX_1:def 8; then A322: f/.k in rng Li1 by A318,A319,A320,PARTFUN2:4; then A323: mi<=i1 by A310,A315,A319,FINSEQ_3:27; consider j1,j2 be Nat such that A324: [j1,j2] in Indices G1 & f/.(k+1)=G1*(j1,j2) by A93,A311; reconsider Lj1 = Line(G1,j1) as FinSequence of TOP-REAL 2; A325: Seg len Lj1 = dom Lj1 by FINSEQ_1:def 3; A326: j1 in dom G1 & j2 in Seg width G1 by A85,A324,ZFMISC_1:106; A327: len Lj1=width G1 by MATRIX_1:def 8; then Lj1/.j2 = Lj1.j2 by A325,A326,FINSEQ_4:def 4; then f/.(k+1)=Lj1/.j2 by A324,A326,MATRIX_1:def 8; then A328: f/.(k+1) in rng Lj1 by A325,A326,A327,PARTFUN2:4; now per cases by A323,REAL_1:def 5; suppose A329: mi=i1; A330: f/.k=f1/.(w+k) & f1/.(w+k)=g1/.(w+k) & w+k in dom g1 by A72,A76,A77,A316; g1/.(w+k) = f1/.(w+k) by A72,A77,A316 .= f/.k by A76,A77,A316 .= Li1/.i2 by A317,A319,A321,MATRIX_1:def 8; then A331: g1/.(w+k) in rng Line(G1,mi) by A318,A319,A320, A329,PARTFUN2:4; w+1<=w+k by A315,REAL_1:55; then w+k<=ma1 & ma1<=w+k by A31,A330,A331,XCMPLX_1:27; then w+k=ma1 by AXIOMS:21; then A332: ma1+1=w+(k+1) by XCMPLX_1:1; A333: f/.(k+1)=f1/.(w+(k+1)) & f1/.(w+(k+1))=g1/.(w+(k+1)) & w+(k+1) in dom g1 & ma-1+(k+1)=ma-1+k+1 by A72,A76,A77,A311,XCMPLX_1:1; mi+1<=ma & mi<=mi+1 by A69,NAT_1:38; then 1<=mi+1 & mi+1<=len G1 by A28,AXIOMS:22; then A334: mi+1 in dom G1 by FINSEQ_3:27; then f/.(k+1) in rng Line(G1,mi+1) by A5,A25,A31,A332,A333,GOBOARD1:44; then m=mi+1 & mi<=mi+1 by A312,A334,GOBOARD1:19,NAT_1:29; hence thesis; suppose A335: mi<i1; now per cases by A241,A311,A316,A319,A322,GOBOARD1:43; suppose f/.(k+1) in rng Line(G1,i1); hence mi<=m by A312,A319,A335,GOBOARD1:19; suppose for l be Nat st f/.(k+1) in rng Line(G1,l) & l in dom G1 holds abs(i1-l)=1; then A336: abs(i1-j1)=1 by A326,A328; now per cases by A336,GOBOARD1:1; suppose A337: j1<i1 & i1=j1+1; mi+1<=i1 by A335,NAT_1:38; then mi<=i1-1 & i1-1=j1 by A337,REAL_1:84,XCMPLX_1:26; hence mi<=m by A312,A326,A328,GOBOARD1:19; suppose i1<j1 & j1=i1+1; then mi<j1 by A335,AXIOMS:22; hence mi<=m by A312,A326,A328,GOBOARD1:19; end; hence thesis; end; hence thesis; end; hence thesis; end; hence thesis; end; A338: for n holds PP[n] from Ind(A308,A309); A339: rng h1 /\ rng tt = {} proof assume A340: not thesis; consider x being Element of rng h1 /\ rng tt; A341: x in rng h1 & x in rng tt by A340,XBOOLE_0:def 3; then x in rng t by A243; then consider i1 be Nat such that A342: i1 in dom f & f/.i1=x by A242,PARTFUN2:4; consider n1,n2 be Nat such that A343: [n1,n2] in Indices G1 & f/.i1=G1*(n1,n2) by A93,A342; reconsider Ln1 = Line(G1,n1) as FinSequence of TOP-REAL 2; A344: Seg len Ln1 = dom Ln1 by FINSEQ_1:def 3; A345: n1 in dom G1 & n2 in Seg width G1 by A85,A343,ZFMISC_1:106; A346: len Ln1=width G1 by MATRIX_1:def 8; then Ln1/.n2 = Ln1.n2 by A344,A345,FINSEQ_4:def 4; then f/.i1=Ln1/.n2 by A343,A345,MATRIX_1:def 8; then f/.i1 in rng Ln1 by A344,A345,A346,PARTFUN2:4; then A347: mi<=n1 by A338,A342,A345; consider i2 be Nat such that A348: i2 in dom h1 & h1/.i2=x by A341,PARTFUN2:4; A349: Seg len h1 = dom h1 by FINSEQ_1:def 3; A350: x=G1*(i2,K1) & i2 in dom G1 by A291,A295,A348; then [i2,K1] in Indices G1 by A85,A256,A257,A258,ZFMISC_1:106; then A351: i2=n1 & n2=K1 by A342,A343,A350,GOBOARD1:21; l1<mi & i2<=l1 by A291,A348,A349,FINSEQ_1:3,SQUARE_1:29; hence contradiction by A347,A351,AXIOMS:22; end; defpred PP[Nat] means $1 in dom f implies for m st m in dom G1 & f/.$1 in rng Line(G1,m) holds m<=ma; A352: PP[0] by FINSEQ_3:27; A353: for k st PP[k] holds PP[k+1] proof let k such that A354: PP[k]; assume A355: k+1 in dom f; let m such that A356: m in dom G1 & f/.(k+1) in rng Line(G1,m); now per cases; suppose A357: k=0; 1 in Seg l by A84,FINSEQ_1:3; then f/.1=f1/.(w+1) & f1/.(w+1)=g1/.(w+1) by A72,A76; then f/.1=Li/.k1 by A51,XCMPLX_1:27; then f/.(k+1) in rng Li by A51,A357,PARTFUN2:4; hence m<=ma by A25,A68,A356,GOBOARD1:19; suppose k<>0; then A358: 0<k & k<=k+1 & k+1<= len f by A83,A355,FINSEQ_1:3,NAT_1:19,29; then A359: 0+1<=k & k<=len f by NAT_1:38; then A360: k in dom f by FINSEQ_3:27; then consider i1,i2 be Nat such that A361: [i1,i2] in Indices G1 & f/.k=G1*(i1,i2) by A93; reconsider Li1 = Line(G1,i1) as FinSequence of TOP-REAL 2; A362: Seg len Li1 = dom Li1 by FINSEQ_1:def 3; A363: i1 in dom G1 & i2 in Seg width G1 by A85,A361,ZFMISC_1:106; A364: len Li1=width G1 by MATRIX_1:def 8; then Li1/.i2 = Li1.i2 by A362,A363,FINSEQ_4:def 4; then f/.k=Li1/.i2 by A361,A363,MATRIX_1:def 8; then A365: f/.k in rng Li1 by A362,A363,A364,PARTFUN2:4; then A366: i1<=ma by A354,A359,A363,FINSEQ_3:27; consider j1,j2 be Nat such that A367: [j1,j2] in Indices G1 & f/.(k+1)=G1*(j1,j2) by A93,A355; reconsider Lj1 = Line(G1,j1) as FinSequence of TOP-REAL 2; A368: Seg len Lj1 = dom Lj1 by FINSEQ_1:def 3; A369: j1 in dom G1 & j2 in Seg width G1 by A85,A367,ZFMISC_1:106; A370: len Lj1=width G1 by MATRIX_1:def 8; then Lj1/.j2 = Lj1.j2 by A368,A369,FINSEQ_4:def 4; then f/.(k+1)=Lj1/.j2 by A367,A369,MATRIX_1:def 8; then A371: f/.(k+1) in rng Lj1 by A368,A369,A370,PARTFUN2:4; then A372: j1=m by A356,A369,GOBOARD1:19; now per cases by A366,REAL_1:def 5; case A373: ma=i1; A374: f/.k=f1/.(w+k) & w is Nat & f1/.(w+k)=g1/.(w+k) & w+k in dom g1 & f/.(k+1)=f1/.(w+(k+1)) & f1/.(w+(k+1))=g1/.(w+(k+1)) & w+(k+1) in dom g1 & ma-1+(k+1)=ma-1+k+1 by A72,A76,A77,A355,A360,XCMPLX_1:1; w+1<=w+k by A359,REAL_1:55; then A375: ma1<=w+k by XCMPLX_1:27; ma1 <> w+k by A25,A27,A31,A67,A365,A373,A374,GOBOARD1:19; then ma1<w+k by A375,REAL_1:def 5; then A376: mi1<=w+k by A71,A365,A373,A374; w+k<=mi1 by A76,A100,A359,REAL_1:55; then w+k=mi1 by A376,AXIOMS:21; then k=mi1-w by XCMPLX_1:26 .=mi1-ma1+1 by XCMPLX_1:37 .=len f by A76,XCMPLX_1:29; hence contradiction by A358,NAT_1:38; case A377: i1<ma; now per cases by A241,A355,A360,A363,A365,GOBOARD1:43; suppose f/.(k+1) in rng Line(G1,i1); hence m<=ma by A356,A363,A377,GOBOARD1:19; suppose for l be Nat st f/.(k+1) in rng Line(G1,l) & l in dom G1 holds abs(i1-l)=1; then A378: abs(i1-j1)=1 by A369,A371; now per cases by A378,GOBOARD1:1; suppose j1<i1 & i1=j1+1; hence m<=ma by A372,A377,AXIOMS:22; suppose i1<j1 & j1=i1+1; hence m<=ma by A372,A377,NAT_1:38; end; hence thesis; end; hence thesis; end; hence thesis; end; hence thesis; end; A379: for n holds PP[n] from Ind(A352,A353); A380: rng h2 /\ rng tt = {} proof assume A381: not thesis; consider x being Element of rng h2 /\ rng tt; A382: x in rng h2 & x in rng tt by A381,XBOOLE_0:def 3; then x in rng t by A243; then consider i1 be Nat such that A383: i1 in dom f & f/.i1=x by A242,PARTFUN2:4; consider n1,n2 be Nat such that A384: [n1,n2] in Indices G1 & f/.i1=G1*(n1,n2) by A93,A383; reconsider Ln1 = Line(G1,n1) as FinSequence of TOP-REAL 2; A385: Seg len Ln1 = dom Ln1 by FINSEQ_1:def 3; A386: n1 in dom G1 & n2 in Seg width G1 by A85,A384,ZFMISC_1:106; A387: len Ln1=width G1 by MATRIX_1:def 8; then Ln1/.n2 = Ln1.n2 by A385,A386,FINSEQ_4:def 4; then f/.i1=Ln1/.n2 by A384,A386,MATRIX_1:def 8; then f/.i1 in rng Ln1 by A385,A386,A387,PARTFUN2:4; then A388: n1<=ma by A379,A383,A386; consider i2 be Nat such that A389: i2 in dom h2 & h2/.i2=x by A382,PARTFUN2:4; A390: x=G1*(ma+i2,K2) & ma+i2 in dom G1 by A293,A297,A389; then [ma+i2,K2] in Indices G1 by A85,A273,A274,A275,ZFMISC_1:106; then A391: ma+i2=n1 & n2=K2 by A383,A384,A390,GOBOARD1:21; 0+1<=i2 by A389,FINSEQ_3:27; then 0<i2 by NAT_1:38; hence contradiction by A388,A391,REAL_2:174; end; now per cases by A250,REAL_1:def 5; suppose A392: pf<pl; set F1=g|pl; pf<=pl & pl<=pl+1 by A392,NAT_1:29; then pf<=pl+1 by AXIOMS:22; then reconsider LL=pl+1-pf as Nat by INT_1:18; reconsider w1=pf-1 as Nat by A251,INT_1:18; A393: for n st n in Seg LL holds F1/.(w1+n)=g/.(w1+n) & w1+n in dom g proof let n such that A394: n in Seg LL; 0+1<=pf by A19,A248,FINSEQ_1:3; then 0<=w1 & 1<=n & n<=LL by A394,FINSEQ_1:3,REAL_1:84; then A395: 0+1<=w1+n & n+pf<=LL+pf by REAL_1:55; then n+pf<=pl+1 by XCMPLX_1:27; then n+pf-1<=pl by REAL_1:86; then w1+n<=pl by XCMPLX_1:29; then w1+n in Seg pl by A395,FINSEQ_1:3; hence thesis by A249,GOBOARD1:10; end; defpred P[Nat, Element of TOP-REAL 2] means $2 = F1/.(w1+$1); A396: for n st n in Seg LL ex p st P[n,p]; consider F be FinSequence of TOP-REAL 2 such that A397: len F = LL & for n st n in Seg LL holds P[n,F/.n] from FinSeqDChoice(A396); A398: Seg len F = dom F by FINSEQ_1:def 3; set FF = h1^F^h2; pf+1<=pl & pl<=pl+1 by A392,NAT_1:38; then pf+1<=pl+1 & dom F=dom F by AXIOMS:22; then A399: 1<=LL & len F=LL by A397,REAL_1:84; now let n; assume n in dom F; then A400: n in Seg LL & dom F=Seg LL & F/.n= F1/.(w1+n) by A397,A398; then A401: w1 is Nat & w1+n in dom g & F/.n=g/.(w1+n) by A393; reconsider w=w1 as Nat; consider i,j such that A402: [i,j] in Indices G1 & g/.(w+n)=G1*(i,j) by A10,A401,GOBOARD1:def 11; take i,j; thus [i,j] in Indices G1 & F/.n=G1*(i,j) by A393,A400,A402; end; then A403: for n st n in dom(h1^F) ex i,j st [i,j] in Indices G1 & (h1^F)/.n=G1*(i,j) by A298,GOBOARD1:39; A404: w1+LL=w1+(pl-pf+1) by XCMPLX_1:29 .= w1+(pl-(w1)) by XCMPLX_1:37 .= pl by XCMPLX_1:27; A405: now let n; assume n in dom F & n+1 in dom F; then n in Seg LL & n+1 in Seg LL & dom F=Seg LL & F/.n=F1/.(w1+n) & F/.(n+1)=F1/.(w1+(n+1)) & w1+(n+1)=w1+n+1 by A397,A398,XCMPLX_1:1; then A406: w1 is Nat & w1+n in dom g & F/.n=g/.(w1+n) & w1+n+1 in dom g & F/.(n+1)=g/.(w1+n+1) by A393; let i1,i2,j1,j2 be Nat; assume [i1,i2] in Indices G1 & [j1,j2] in Indices G1 & F/.n=G1*(i1,i2) & F/.(n+1)=G1*(j1,j2); hence abs(i1-j1)+abs(i2-j2)=1 by A10,A406,GOBOARD1:def 11; end; A407: now let i1,i2,j1,j2 be Nat; assume A408: [i1,i2] in Indices G1 & [j1,j2] in Indices G1 & h1/.len h1=G1*(i1,i2) & F/.1=G1*(j1,j2) & len h1 in dom h1 & 1 in dom F; then A409: h1/.len h1=G1*(l1,K1) & l1 in dom G1 by A291,A295; then [l1,K1] in Indices G1 by A85,A256,A257,A258,ZFMISC_1:106; then A410: i1=l1 & i2=K1 & 0<=1 by A408,A409,GOBOARD1:21; 1 in Seg LL & dom F=Seg LL & F/.1=F1/.(w1+1) by A397,A398,A408; then A411: F/.1=g/.(w1+1) by A393 .= G1*(mi,K1) by A259,XCMPLX_1:27; [mi,K1] in Indices G1 by A25,A85,A256,A257,A258,ZFMISC_1:106; then j1=mi & j2=K1 by A408,A411,GOBOARD1:21; hence abs(i1-j1)+abs(i2-j2)= abs(mi-1-mi)+abs(0) by A410,XCMPLX_1:14 .= abs(mi-1-mi)+0 by ABSVALUE:7 .= abs(mi+-1-mi) by XCMPLX_0:def 8 .= abs(-1) by XCMPLX_1:26 .= abs(1) by ABSVALUE:17 .= 1 by ABSVALUE:def 1; end; set hf=h1^F; A412: now let i1,i2,j1,j2 be Nat; assume A413: [i1,i2] in Indices G1 & [j1,j2] in Indices G1 & hf/.len hf=G1*( i1,i2) & h2/.1=G1*(j1,j2) & len hf in dom hf & 1 in dom h2; then A414: h2/.1=G1*(ma+1,K2) & ma+1 in dom G1 by A293,A297; then [ma+1,K2] in Indices G1 by A85,A273,A274,A275,ZFMISC_1:106; then A415: j1=ma+1 & j2=K2 by A413,A414,GOBOARD1:21; A416: len F in dom F & 0<=1 by A398,A399,FINSEQ_1:3; A417: hf/.len hf=hf/.(len h1+len F) by FINSEQ_1:35 .= F/.len F by A416,GROUP_5:96 .= F1/.(w1+LL) by A397,A398,A416 .= G1*(ma,K2) by A276,A393,A397,A398,A404,A416; [ma,K2] in Indices G1 by A27,A85,A273,A274,A275,ZFMISC_1:106; then i1=ma & i2=K2 by A413,A417,GOBOARD1:21; hence abs(i1-j1)+abs(i2-j2)=abs(ma-(ma+1))+abs(0) by A415,XCMPLX_1:14 .=abs(ma-(ma+1))+0 by ABSVALUE:7 .=abs(-(ma+1 -ma)) by XCMPLX_1:143 .=abs(ma+1 -ma) by ABSVALUE:17 .=abs(1) by XCMPLX_1:26 .=1 by ABSVALUE:def 1; end; A418: FF is_sequence_on G1 proof thus for n st n in dom FF ex i,j st [i,j] in Indices G1 & FF/.n=G1*(i,j) by A300,A403,GOBOARD1:39; for n st n in dom(h1^F) & n+1 in dom(h1^F) for i1,i2,j1,j2 be Nat st [i1,i2] in Indices G1 & [j1,j2] in Indices G1 & (h1^F)/.n=G1*(i1,i2) & (h1^F)/.(n+1)=G1*(j1,j2) holds abs(i1-j1)+abs(i2-j2)=1 by A302,A405,A407,GOBOARD1:40; hence for n st n in dom FF & n+1 in dom FF for m,k,i,j st [m,k] in Indices G1 & [i,j] in Indices G1 & FF/.n=G1*(m,k) & FF/.(n+1)=G1*(i,j) holds abs(m-i)+abs(k-j)=1 by A305,A412,GOBOARD1:40; end; A419: now per cases; suppose A420: mi=1; then h1 = {} by A291,FINSEQ_1:25; then A421: FF=F^h2 by FINSEQ_1:47; A422: 1 in Seg LL & 1<=pf by A19,A248,A399,FINSEQ_1:3; A423: pf in Seg pl by A251,A392,FINSEQ_1:3; FF/.1=F/.1 by A397,A398,A421,A422,GROUP_5:95 .= F1/.(w1+1) by A397,A422 .= F1/.pf by XCMPLX_1:27 .= g/.pf by A249,A423,GOBOARD1:10; hence FF/.1 in rng Line(G1,1) by A248,A420; suppose A424: mi<>1; 1<=mi by A25,FINSEQ_3:27; then 1<mi by A424,REAL_1:def 5; then 1+1<=mi by NAT_1:38; then A425: 1<=l1 by REAL_1:84; then A426: 1 in Seg l1 by FINSEQ_1:3; A427: len(h1^F)=len h1 + len F by FINSEQ_1:35; len Line(G1,1)=width G1 by MATRIX_1:def 8; then A428: K1 in dom L1 by A256,A257,A258,FINSEQ_1:def 3; then A429: L1/.K1 = L1.K1 by FINSEQ_4:def 4; 0<=len F by NAT_1:18; then 0+1<=len(h1^F) by A291,A425,A427,REAL_1:55; then 1 in dom(h1^F) by FINSEQ_3:27; then FF/.1=(h1^F)/.1 by GROUP_5:95 .=h1/.1 by A291,A292,A426,GROUP_5:95 .=G1*(1,K1) by A291,A292,A426 .=L1/.K1 by A256,A257,A258,A429,MATRIX_1:def 8; hence FF/.1 in rng Line(G1,1) by A428,PARTFUN2:4; end; A430: len FF=len(h1^F)+len h2 by FINSEQ_1:35 .=len h1+len F+len h2 by FINSEQ_1:35; 0+0<=len h1+len h2 by NAT_1:18; then 0+1<=len F+(len h1+len h2) by A399,REAL_1:55; then A431: 1<=len FF by A430,XCMPLX_1:1; A432: now per cases; suppose A433: ma=len G1; then l2=0 & g/.pl in rng Line(G1,len G1) by A249,XCMPLX_1:14; then h2 = {} by A293,FINSEQ_1:25; then A434: FF=h1^F & 1<=pl by A19,A249,FINSEQ_1:3,47; then A435: len F in dom F & pl in Seg pl by A399,FINSEQ_1:3,FINSEQ_3: 27; FF/.len FF=FF/.(len h1+len F) by A434,FINSEQ_1:35 .= F/.LL by A397,A434,A435,GROUP_5:96 .= F1/.pl by A397,A398,A404,A435 .= g/.pl by A249,A435,GOBOARD1:10; hence FF/.len FF in rng Line(G1,len G1) by A249,A433; suppose A436: ma<>len G1; ma<=len G1 by A27,FINSEQ_3:27; then ma<len G1 by A436,REAL_1:def 5; then ma+1<=len G1 by NAT_1:38; then A437: 1<=l2 by REAL_1:84; then A438: l2 in Seg l2 by FINSEQ_1:3; len Line(G1,len G1)=width G1 by MATRIX_1:def 8; then A439: K2 in dom Ll by A273,A274,A275,FINSEQ_1:def 3; then A440: Ll/.K2 = Ll.K2 by FINSEQ_4:def 4; A441: len h2 in dom h2 by A293,A437,FINSEQ_3:27; FF/.len FF=FF/.(len(h1^F)+len h2) by FINSEQ_1:35 .=h2/.l2 by A293,A441,GROUP_5:96 .=G1*(ma+l2,K2) by A293,A294,A438 .=G1*(len G1,K2) by XCMPLX_1:27 .=Ll/.K2 by A273,A274,A275,A440,MATRIX_1:def 8; hence FF/.len FF in rng Line(G1,len G1) by A439,PARTFUN2:4; end; A442: rng FF = rng(h1^F) \/ rng h2 by FINSEQ_1:44 .= rng h1 \/ rng F \/ rng h2 by FINSEQ_1:44; A443: for k st k in Seg width G1 & rng F /\ rng Col(G1,k)={} holds rng FF /\ rng Col(G1,k)={} proof let k; assume that A444: k in Seg width G1 and A445: rng F /\ rng Col(G1,k)={}; set gg=Col(G1,k); assume A446: rng FF /\ rng gg <> {}; consider x being Element of rng FF /\ rng gg; rng FF = rng F \/ (rng h1 \/ rng h2) by A442,XBOOLE_1:4; then A447: rng FF /\ rng gg = {} \/ (rng h1 \/ rng h2) /\ rng gg by A445,XBOOLE_1:23 .= rng h1 /\ rng gg \/ rng h2 /\ rng gg by XBOOLE_1:23; A448: len Col(G1,K1)=len G1 & len Col(G1,K2)=len G1 by MATRIX_1:def 9; now per cases by A446,A447,XBOOLE_0:def 2; suppose x in rng h1 /\ rng gg; then A449: x in rng h1 & x in rng gg by XBOOLE_0:def 3; then consider i such that A450: i in dom h1 & x=h1/.i by PARTFUN2:4; A451: x=G1*(i,K1) by A291,A450; reconsider y=x as Point of TOP-REAL 2 by A450; A452: dom CK1 = Seg len G1 by A448,FINSEQ_1:def 3 .= dom G1 by FINSEQ_1:def 3; then A453: i in dom CK1 by A295,A450; A454: Lmi/.K1 = Lmi.K1 & CK1/.mi = CK1.mi by A25,A256,A452,FINSEQ_4:def 4; CK1/.i = CK1.i by A453,FINSEQ_4:def 4; then y=CK1/.i by A451,A452,A453,MATRIX_1:def 9; then y in rng CK1 by A453,PARTFUN2:4; then A455: K1=k & 1 in Seg LL by A256,A257,A258,A399,A444,A449,FINSEQ_1:3,GOBOARD1:20; then F/.1=F1/.(w1+1) & F1/.(w1+1)=g/.(w1+1) by A393,A397; then F/.1=Lmi/.K1 by A256,XCMPLX_1:27 .= CK1/.mi by A25,A256,A257,A258,A454,GOBOARD1:17; then F/.1 in rng Col(G1,k) & F/.1 in rng F by A25,A397,A398,A452,A455,PARTFUN2:4; hence contradiction by A445,XBOOLE_0:def 3; suppose x in rng h2 /\ rng gg; then A456: x in rng h2 & x in rng gg by XBOOLE_0:def 3; then consider i such that A457: i in dom h2 & x=h2/.i by PARTFUN2:4; A458: x=G1*(ma+i,K2) by A293,A457; reconsider y=x as Point of TOP-REAL 2 by A457; A459: dom CK2 = Seg len G1 by A448,FINSEQ_1:def 3 .= dom G1 by FINSEQ_1:def 3; then A460: ma+i in dom CK2 by A297,A457; A461: Lma/.K2 = Lma.K2 & CK2/.ma = CK2.ma by A27,A273,A459,FINSEQ_4: def 4; A462: LL=pl+(1-pf) by XCMPLX_1:29 .= pl-w1 by XCMPLX_1:38; CK2/.(ma+i) = CK2.(ma+i) by A460,FINSEQ_4:def 4; then y=CK2/.(ma+i) by A458,A459,A460,MATRIX_1:def 9; then y in rng CK2 by A460,PARTFUN2:4; then A463: K2=k by A273,A274,A275,A444,A456,GOBOARD1:20; A464: LL in Seg LL by A399,FINSEQ_1:3; then F/.LL=F1/.(w1+LL) & F1/.(w1+LL)=g/.(w1+LL) by A393,A397; then F/.LL=Lma/.K2 by A273,A462,XCMPLX_1:27 .= CK2/.ma by A27,A273,A274,A275,A461,GOBOARD1:17; then F/.LL in rng Col(G1,k) & F/.LL in rng F by A27,A397,A398,A459,A463,A464,PARTFUN2:4; hence contradiction by A445,XBOOLE_0:def 3; end; hence contradiction; end; A465: rng tt /\ rng FF = ((rng h1 \/ rng F) /\ rng tt) \/ {} by A380,A442,XBOOLE_1:23 .= {} \/ rng F /\ rng tt by A339,XBOOLE_1:23 .= rng tt /\ rng F; rng tt c= rng f by A242,A243,XBOOLE_1:1; then A466: rng tt c= rng g1 by A190,XBOOLE_1:1; rng F c= rng g2 proof let x; assume x in rng F; then consider n such that A467: n in dom F & x=F/.n by PARTFUN2:4; n in Seg LL & n in Seg LL & F/.n= F1/.(w1+n) by A397,A398,A467; then w1 is Nat & w1+n in dom g & F/.n=g/.(w1+n) by A393; then x in rng g by A467,PARTFUN2:4; hence x in rng g2 by A34; end; then A468: rng FF /\ rng tt c= rng g1 /\ rng g2 by A465,A466,XBOOLE_1:27 ; A469: 1 in dom FF & len FF in dom FF by A431,FINSEQ_3:27; rng F /\ rng C = {} proof assume A470: not thesis; consider x being Element of rng F /\ rng C; A471: x in rng F & x in rng C by A470,XBOOLE_0:def 3; then consider i1 be Nat such that A472: i1 in dom F & F/.i1=x by PARTFUN2:4; A473: Seg len F = dom F by FINSEQ_1:def 3; then A474: F/.i1=F1/.(w1+i1) & w1 is Nat & F1/.(w1+i1)= g/.(w1+i1) & w1+i1 in dom g by A393,A397,A472; reconsider w=w1 as Nat; g2/.(w+i1) in rng C & w+i1 in dom g2 by A8,A19,A33,A471,A472,A474,GOBOARD1:10; then A475: m<=w+i1 & i1<=LL by A8,A397,A472,A473,FINSEQ_1:3; then w+i1<=w+LL by REAL_1:55; hence contradiction by A33,A290,A404,A475,AXIOMS:22; end; then rng FF /\ rng Col(G1,width G1) = {} by A15,A443; then rng FF misses rng Col(G1,width G1) by XBOOLE_0:def 7; then A476: FF is_sequence_on D & FF/.1 in rng Line(D,1) & FF/.len FF in rng Line(D,len D) by A15,A16,A17,A193,A194,A418,A419,A432,A469,GOBOARD1:37,41; width D=k by A5,A15,A66,GOBOARD1:26; then A477: rng FF /\ rng tt <> {} by A4,A66,A243,A431,A476; consider x being Element of rng FF /\ rng tt; x in rng FF /\ rng tt by A477; hence thesis by A468; suppose A478: pl<pf; set F1=g|pf; pl<=pf & pf<=pf+1 by A478,NAT_1:29; then pl<=pf+1 by AXIOMS:22; then reconsider LL=pf+1-pl as Nat by INT_1:18; A479: for n st n in Seg LL holds pf+1-n is Nat proof let n; assume n in Seg LL; then A480: 1<=n & n<=LL & 0<=pl by FINSEQ_1:3,NAT_1:18; then LL<=pf+1-0 by REAL_1:92; then n<=pf+1 by A480,AXIOMS:22; hence thesis by INT_1:18; end; A481: for n,k st n in Seg LL & k = pf+1-n holds F1/.k=g/.k & k in dom g proof let n,k; assume that A482: n in Seg LL and A483: k = pf+1-n; A484: 1<=n & n<=LL & 0<=pl by A482,FINSEQ_1:3,NAT_1:18; then LL<=pf+1-0 by REAL_1:92; then n<=pf+1 by A484,AXIOMS:22; then reconsider w=pf+1-n as Nat by INT_1:18; pf+1-n<=pf+1-1 & pf+1-LL<=pf+1-n by A484,REAL_1:92; then A485: pf+1-n<=pf & pl<=pf+1-n by XCMPLX_1:18,26; then 1<=pf+1-n by A251,AXIOMS:22; then w in Seg pf by A485,FINSEQ_1:3; hence thesis by A248,A483,GOBOARD1:10; end; defpred P[Nat,Element of TOP-REAL 2] means for k st k = pf+1-$1 holds $2 = F1/.k; A486: for n st n in Seg LL ex p st P[n,p] proof let n; assume A487: n in Seg LL; then reconsider k = pf+1-n as Nat by A479; take g/.k; thus thesis by A481,A487; end; consider F be FinSequence of TOP-REAL 2 such that A488: len F = LL & for n st n in Seg LL holds P[n,F/.n] from FinSeqDChoice(A486); A489: Seg len F = dom F by FINSEQ_1:def 3; set FF = h1^F^h2; pl+1<=pf & pf<=pf+1 by A478,NAT_1:38; then pl+1<=pf+1 & dom F=dom F by AXIOMS:22; then A490: 1<=LL & len F=LL by A488,REAL_1:84; now let n; assume A491: n in dom F; then reconsider w=pf+1-n as Nat by A479,A488,A489; A492: n in Seg LL & dom F=Seg LL & F/.n=F1/.w by A488,A489,A491; then pf+1-n is Nat & pf+1-n in dom g & F/.n=g/.w by A481; then consider i,j such that A493: [i,j] in Indices G1 & g/.w=G1*(i,j) by A10,GOBOARD1:def 11; take i,j; thus [i,j] in Indices G1 & F/.n=G1*(i,j) by A481,A492,A493; end; then for n st n in dom(h1^F) ex i,j st [i,j] in Indices G1 & (h1^F)/.n=G1*(i,j) by A298,GOBOARD1:39; then A494: for n st n in dom FF ex i,j st [i,j] in Indices G1 & FF/.n=G1*(i,j) by A300,GOBOARD1:39; A495: now let n; assume A496: n in dom F & n+1 in dom F; then reconsider w3=pf+1-n, w2=pf+1-(n+1) as Nat by A479,A488,A489; A497: n in Seg LL & n+1 in Seg LL & dom F=Seg LL & F/.n=F1/.w3 & F/.(n+1)=F1/.w2 & pf+1-(n+1)=pf+1-n-1 by A488,A489,A496,XCMPLX_1:36; then A498: pf+1-n in dom g & F/.n=g/.w3 & pf+1-(n+1) in dom g & F/.(n+1)=g/.w2 by A481; A499: w2+1=pf+1-n by A497,XCMPLX_1:27; let i1,i2,j1,j2 be Nat; assume [i1,i2] in Indices G1 & [j1,j2] in Indices G1 & F/.n=G1*(i1,i2) & F/.(n+1)=G1*(j1,j2); hence 1=abs(j1-i1)+abs(j2-i2) by A10,A498,A499,GOBOARD1:def 11 .= abs(-(i1-j1))+abs(j2-i2) by XCMPLX_1:143 .= abs(-(i1-j1))+abs(-(i2-j2)) by XCMPLX_1:143 .= abs(i1-j1)+abs(-(i2-j2)) by ABSVALUE:17 .= abs(i1-j1)+abs(i2-j2) by ABSVALUE:17; end; A500: pf+1-1 = pf by XCMPLX_1:26; now let i1,i2,j1,j2 be Nat; assume A501: [i1,i2] in Indices G1 & [j1,j2] in Indices G1 & h1/.len h1=G1*(i1,i2) & F/.1=G1*(j1,j2) & len h1 in dom h1 & 1 in dom F; then A502: h1/.len h1=G1*(l1,K1) & l1 in dom G1 by A291,A295; then [l1,K1] in Indices G1 by A85,A256,A257,A258,ZFMISC_1:106; then A503: i1=l1 & i2=K1 & 0<=1 by A501,A502,GOBOARD1:21; reconsider w4 = pf + 1 - 1 as Nat by XCMPLX_1:26; A504: F/.1 = F1/.w4 by A488,A489,A501 .= g/.w4 by A481,A488,A489,A501 .= G1*(mi,K1) by A259,XCMPLX_1:26; [mi,K1] in Indices G1 by A25,A85,A256,A257,A258,ZFMISC_1:106; then j1=mi & j2=K1 by A501,A504,GOBOARD1:21; hence abs(i1-j1)+abs(i2-j2)= abs(mi-1-mi)+abs(0) by A503,XCMPLX_1:14 .= abs(mi-1-mi)+0 by ABSVALUE:7 .= abs(mi+-1-mi) by XCMPLX_0:def 8 .= abs(-1) by XCMPLX_1:26 .= abs(1) by ABSVALUE:17 .= 1 by ABSVALUE:def 1; end; then A505: for n st n in dom(h1^F) & n+1 in dom(h1^F) for i1,i2,j1,j2 be Nat st [i1,i2] in Indices G1 & [j1,j2] in Indices G1 & (h1^F)/.n=G1*(i1,i2) & (h1^F)/.(n+1)=G1*(j1,j2) holds abs(i1-j1)+abs(i2-j2)=1 by A302,A495,GOBOARD1:40; set hf=h1^F; now let i1,i2,j1,j2 be Nat; assume A506:[i1,i2] in Indices G1 & [j1,j2] in Indices G1 & hf/.len hf=G1*(i1,i2) & h2/.1=G1*(j1,j2) & len hf in dom hf & 1 in dom h2; then A507: h2/.1=G1*(ma+1,K2) & ma+1 in dom G1 by A293,A297; then [ma+1,K2] in Indices G1 by A85,A273,A274,A275,ZFMISC_1:106; then A508: j1=ma+1 & j2=K2 by A506,A507,GOBOARD1:21; A509: len F in dom F & 0<=1 by A490,FINSEQ_3:27; LL in Seg LL by A490,FINSEQ_1:3; then reconsider u = pf+1-LL as Nat by A479; A510: hf/.len hf=hf/.(len h1+len F) by FINSEQ_1:35 .= F/.len F by A509,GROUP_5:96 .= F1/.u by A488,A489,A509 .= g/.u by A481,A488,A489,A509 .= G1*(ma,K2) by A276,XCMPLX_1:18; [ma,K2] in Indices G1 by A27,A85,A273,A274,A275,ZFMISC_1:106; then i1=ma & i2=K2 by A506,A510,GOBOARD1:21; hence abs(i1-j1)+abs(i2-j2)=abs(ma-(ma+1))+abs(0) by A508,XCMPLX_1:14 .=abs(ma-(ma+1))+0 by ABSVALUE:7 .=abs(-(ma+1 -ma)) by XCMPLX_1:143 .=abs(ma+1 -ma) by ABSVALUE:17 .=abs(1) by XCMPLX_1:26 .=1 by ABSVALUE:def 1; end; then for n st n in dom FF & n+1 in dom FF for m,k,i,j st [m,k] in Indices G1 & [i,j] in Indices G1 & FF/.n=G1*(m,k) & FF/.(n+1)=G1*(i,j) holds abs(m-i)+abs(k-j)=1 by A305,A505,GOBOARD1:40; then A511: FF is_sequence_on G1 by A494,GOBOARD1:def 11; A512: now per cases; suppose A513: mi=1; then h1 = {} by A291,FINSEQ_1:25; then A514: FF=F^h2 by FINSEQ_1:47; A515: 1 in Seg LL & 1<=pl by A19,A249,A490,FINSEQ_1:3; A516: pf in Seg pf by A251,FINSEQ_1:3; FF/.1=F/.1 by A488,A489,A514,A515,GROUP_5:95 .= F1/.pf by A488,A500,A515 .= g/.pf by A248,A516,GOBOARD1:10; hence FF/.1 in rng Line(G1,1) by A248,A513; suppose A517: mi<>1; 1<=mi by A25,FINSEQ_3:27; then 1<mi by A517,REAL_1:def 5; then 1+1<=mi by NAT_1:38; then A518: 1<=l1 by REAL_1:84; then A519: 1 in Seg l1 by FINSEQ_1:3; A520: len(h1^F)=len h1 + len F by FINSEQ_1:35; len Line(G1,1)=width G1 by MATRIX_1:def 8; then A521: K1 in dom L1 by A256,A257,A258,FINSEQ_1:def 3; then A522: L1/.K1 = L1.K1 by FINSEQ_4:def 4; 0<=len F by NAT_1:18; then 0+1<=len(h1^F) by A291,A518,A520,REAL_1:55; then 1 in dom(h1^F) by FINSEQ_3:27; then FF/.1=(h1^F)/.1 by GROUP_5:95 .=h1/.1 by A291,A292,A519,GROUP_5:95 .=G1*(1,K1) by A291,A292,A519 .=L1/.K1 by A256,A257,A258,A522,MATRIX_1:def 8; hence FF/.1 in rng Line(G1,1) by A521,PARTFUN2:4; end; A523: len FF=len(h1^F)+len h2 by FINSEQ_1:35 .=len h1+len F+len h2 by FINSEQ_1:35; 0+0<=len h1+len h2 by NAT_1:18; then 0+1<=len F+(len h1+len h2) by A490,REAL_1:55; then A524: 1<=len FF by A523,XCMPLX_1:1; A525: now per cases; suppose A526: ma=len G1; then l2=0 & g/.pl in rng Line(G1,len G1) by A249,XCMPLX_1:14; then h2 = {} by A293,FINSEQ_1:25; then A527: FF=h1^F by FINSEQ_1:47; A528: pf+1-(pf+1-pl) = pl by XCMPLX_1:18; A529: len F in dom F & pl in Seg pf by A251,A478,A490,FINSEQ_1:3,FINSEQ_3:27; FF/.len FF=FF/.(len h1+len F) by A527,FINSEQ_1:35 .= F/.LL by A488,A527,A529,GROUP_5:96 .= F1/.pl by A488,A489,A528,A529 .= g/.pl by A248,A529,GOBOARD1:10; hence FF/.len FF in rng Line(G1,len G1) by A249,A526; suppose A530: ma<>len G1; ma<=len G1 by A27,FINSEQ_3:27; then ma<len G1 by A530,REAL_1:def 5; then ma+1<=len G1 by NAT_1:38; then A531: 1<=l2 by REAL_1:84; then A532: l2 in Seg l2 by FINSEQ_1:3; len Line(G1,len G1)=width G1 by MATRIX_1:def 8; then A533: K2 in dom Ll by A273,A274,A275,FINSEQ_1:def 3; then A534: Ll/.K2 = Ll.K2 by FINSEQ_4:def 4; A535: len h2 in dom h2 by A293,A531,FINSEQ_3:27; FF/.len FF=FF/.(len(h1^F)+len h2) by FINSEQ_1:35 .=h2/.l2 by A293,A535,GROUP_5:96 .=G1*(ma+l2,K2) by A293,A294,A532 .=G1*(len G1,K2) by XCMPLX_1:27 .=Ll/.K2 by A273,A274,A275,A534,MATRIX_1:def 8; hence FF/.len FF in rng Line(G1,len G1) by A533,PARTFUN2:4; end; A536: rng FF = rng(h1^F) \/ rng h2 by FINSEQ_1:44 .= rng h1 \/ rng F \/ rng h2 by FINSEQ_1:44; A537: for k st k in Seg width G1 & rng F /\ rng Col(G1,k)={} holds rng FF /\ rng Col(G1,k)={} proof let k; assume that A538: k in Seg width G1 and A539: rng F /\ rng Col(G1,k)={}; set gg=Col(G1,k); assume A540: rng FF /\ rng gg <> {}; consider x being Element of rng FF /\ rng gg; rng FF = rng F \/ (rng h1 \/ rng h2) by A536,XBOOLE_1:4; then A541: rng FF /\ rng gg = {} \/ (rng h1 \/ rng h2) /\ rng gg by A539,XBOOLE_1:23 .= rng h1 /\ rng gg \/ rng h2 /\ rng gg by XBOOLE_1:23; A542: len Col(G1,K1)=len G1 & len Col(G1,K2)=len G1 by MATRIX_1:def 9; now per cases by A540,A541,XBOOLE_0:def 2; suppose x in rng h1 /\ rng gg; then A543: x in rng h1 & x in rng gg by XBOOLE_0:def 3; then consider i such that A544: i in dom h1 & x=h1/.i by PARTFUN2:4; A545: x=G1*(i,K1) by A291,A544; reconsider y=x as Point of TOP-REAL 2 by A544; A546: pf+1-1 = pf by XCMPLX_1:26; A547: dom CK1 = Seg len G1 by A542,FINSEQ_1:def 3 .= dom G1 by FINSEQ_1:def 3; then A548: i in dom CK1 by A295,A544; A549: Lmi/.K1 = Lmi.K1 & CK1/.mi = CK1.mi by A25,A256,A547,FINSEQ_4:def 4; CK1/.i = CK1.i by A548,FINSEQ_4:def 4; then y=CK1/.i by A545,A547,A548,MATRIX_1:def 9; then y in rng CK1 by A548,PARTFUN2:4; then A550: K1=k & 1 in Seg LL by A256,A257,A258,A490,A538,A543,FINSEQ_1:3,GOBOARD1:20; then F/.1=F1/.pf & F1/.pf=g/.pf by A481,A488,A546; then F/.1=CK1/.mi by A25,A256,A257,A258,A549,GOBOARD1:17; then F/.1 in rng Col(G1,k) & F/.1 in rng F by A25,A488,A489,A547,A550,PARTFUN2:4; hence contradiction by A539,XBOOLE_0:def 3; suppose x in rng h2 /\ rng gg; then A551: x in rng h2 & x in rng gg by XBOOLE_0:def 3; then consider i such that A552: i in dom h2 & x=h2/.i by PARTFUN2:4; A553: x=G1*(ma+i,K2) by A293,A552; reconsider y=x as Point of TOP-REAL 2 by A552; A554: LL in Seg LL by A490,FINSEQ_1:3; then reconsider u = pf+1-LL as Nat by A479; A555: dom CK2 = Seg len G1 by A542,FINSEQ_1:def 3 .= dom G1 by FINSEQ_1:def 3; then A556: ma+i in dom CK2 by A297,A552; A557: Lma/.K2 = Lma.K2 & CK2/.ma = CK2.ma by A27,A273,A555,FINSEQ_4:def 4; CK2/.(ma+i) = CK2.(ma+i) by A556,FINSEQ_4:def 4; then y=CK2/.(ma+i) by A553,A555,A556,MATRIX_1:def 9; then y in rng CK2 by A556,PARTFUN2:4; then A558: K2=k by A273,A274,A275,A538,A551,GOBOARD1:20; F/.LL=F1/.u & F1/.u=g/.u by A481,A488,A554; then F/.LL=Lma/.K2 by A273,XCMPLX_1:18 .= CK2/.ma by A27,A273,A274,A275,A557,GOBOARD1:17; then F/.LL in rng Col(G1,k) & F/.LL in rng F by A27,A488,A489,A554,A555,A558,PARTFUN2:4; hence contradiction by A539,XBOOLE_0:def 3; end; hence contradiction; end; A559: rng tt /\ rng FF = ((rng h1 \/ rng F) /\ rng tt) \/ {} by A380,A536,XBOOLE_1:23 .= {} \/ rng F /\ rng tt by A339,XBOOLE_1:23 .= rng tt /\ rng F; rng tt c= rng f by A242,A243,XBOOLE_1:1; then A560: rng tt c= rng g1 by A190,XBOOLE_1:1; rng F c= rng g2 proof let x; assume x in rng F; then consider n such that A561: n in dom F & x=F/.n by PARTFUN2:4; reconsider u = pf+1-n as Nat by A479,A488,A489,A561; F/.n=F1/.u by A488,A489,A561; then pf+1-n in dom g & F/.n=g/.u by A481,A488,A489,A561; then x in rng g by A561,PARTFUN2:4; hence x in rng g2 by A34; end; then A562: rng FF /\ rng tt c= rng g1 /\ rng g2 by A559,A560,XBOOLE_1:27 ; A563: 1 in dom FF & len FF in dom FF by A524,FINSEQ_3:27; rng F /\ rng C = {} proof assume A564: not thesis; consider x being Element of rng F /\ rng C; A565: x in rng F & x in rng C by A564,XBOOLE_0:def 3; then consider i1 be Nat such that A566: i1 in dom F & F/.i1=x by PARTFUN2:4; reconsider w=pf+1-i1 as Nat by A479,A488,A489,A566; A567: F/.i1=F1/.w & F1/.w=g/.w & w in dom g by A481,A488,A489,A566; 1<=i1 & i1<=LL by A488,A566,FINSEQ_3:27; then w<=pf+1-1 & pf+1-LL<=w by REAL_1:92; then A568: w<=pf & pl<=w by XCMPLX_1:18,26; A569: w in dom g2 by A8,A19,A33,A567,GOBOARD1:10; g2/.w in rng C by A8,A19,A33,A565,A566,A567,GOBOARD1:10; then m<=w & w<m by A8,A33,A272,A568,A569,AXIOMS:22; hence contradiction; end; then rng FF /\ rng Col(G1,width G1) = {} by A15,A537; then rng FF misses rng Col(G1,width G1) by XBOOLE_0:def 7; then A570: FF is_sequence_on D & FF/.1 in rng Line(D,1) & FF/.len FF in rng Line(D,len D) by A15,A16,A17,A193,A194,A511,A512,A525,A563,GOBOARD1:37,41; width D=k by A5,A15,A66,GOBOARD1:26; then A571: rng FF /\ rng tt <> {} by A4,A66,A243,A524,A570; consider x being Element of rng FF /\ rng tt; x in rng FF /\ rng tt by A571; hence thesis by A562; end; hence thesis; end; hence thesis; end; end; hence thesis; end; hence thesis; end; A572: for k holds P[k] from Ind(A2,A3); A573: now let k; let G1,g1,g2; assume k=width G1 & k>0 & 1<=len g1 & 1<=len g2 & g1 is_sequence_on G1 & g2 is_sequence_on G1 & g1/.1 in rng Line(G1,1) & g1/.len g1 in rng Line(G1,len G1) & g2/.1 in rng Col(G1,1) & g2/.len g2 in rng Col(G1,width G1); then rng g1 /\ rng g2 <> {} by A572; hence rng g1 meets rng g2 by XBOOLE_0:def 7; end; width G <> 0 by GOBOARD1:def 5; then width G > 0 by NAT_1:19; hence thesis by A1,A573; end; theorem Th2: for G,f1,f2 st 2<=len f1 & 2<=len f2 & f1 is_sequence_on G & f2 is_sequence_on G & f1/.1 in rng Line(G,1) & f1/.len f1 in rng Line(G,len G) & f2/.1 in rng Col(G,1) & f2/.len f2 in rng Col(G,width G) holds L~f1 meets L~f2 proof let G,f1,f2; assume A1: 2<=len f1 & 2<=len f2 & f1 is_sequence_on G & f2 is_sequence_on G & f1/.1 in rng Line(G,1) & f1/.len f1 in rng Line(G,len G) & f2/.1 in rng Col(G,1) & f2/.len f2 in rng Col(G,width G); then 1<=len f1 & 1<=len f2 by AXIOMS:22; then rng f1 meets rng f2 by A1,Th1; then consider x being set such that A2: x in rng f1 & x in rng f2 by XBOOLE_0:3; A3: ex n st n in dom f1 & f1/.n=x by A2,PARTFUN2:4; ex m st m in dom f2 & f2/.m=x by A2,PARTFUN2:4; then x in L~f1 & x in L~f2 by A1,A3,GOBOARD1:16; hence thesis by XBOOLE_0:3; end; theorem for G,f1,f2 st 2 <= len f1 & 2 <= len f2 & f1 is_sequence_on G & f2 is_sequence_on G & f1/.1 in rng Line(G,1) & f1/.len f1 in rng Line(G,len G) & f2/.1 in rng Col(G,1) & f2/.len f2 in rng Col(G,width G) holds L~f1 meets L~f2 by Th2; definition let f be FinSequence of REAL, r,s be Real; pred f lies_between r,s means :Def1: for n st n in dom f holds r <= f.n & f.n <= s; end; definition let D be non empty set; let f1 be FinSequence of D, f2 be non empty FinSequence of D; cluster f1^f2 -> non empty; coherence by FINSEQ_1:48; cluster f2^f1 -> non empty; coherence by FINSEQ_1:48; end; theorem Th4: for f1,f2 being FinSequence of TOP-REAL 2 st 2<=len f1 & 2<=len f2 & f1 is special & f2 is special & (for n st n in dom f1 & n+1 in dom f1 holds f1/.n <> f1/.(n+1)) & (for n st n in dom f2 & n+1 in dom f2 holds f2/.n <> f2/.(n+1)) & X_axis(f1) lies_between (X_axis(f1)).1, (X_axis(f1)).(len f1) & X_axis(f2) lies_between (X_axis(f1)).1, (X_axis(f1)).(len f1) & Y_axis(f1) lies_between (Y_axis(f2)).1, (Y_axis(f2)).(len f2) & Y_axis(f2) lies_between (Y_axis(f2)).1, (Y_axis(f2)).(len f2) holds L~f1 meets L~f2 proof let f1,f2 be FinSequence of TOP-REAL 2; assume that A1: 2<=len f1 & 2<=len f2 and A2: f1 is special and A3: f2 is special and A4: for n st n in dom f1 & n+1 in dom f1 holds f1/.n <> f1/.(n+1) and A5: for n st n in dom f2 & n+1 in dom f2 holds f2/.n <> f2/.(n+1) and A6: X_axis(f1) lies_between (X_axis(f1)).1, (X_axis(f1)).(len f1) and A7: X_axis(f2) lies_between (X_axis(f1)).1, (X_axis(f1)).(len f1) and A8: Y_axis(f1) lies_between (Y_axis(f2)).1, (Y_axis(f2)).(len f2) and A9: Y_axis(f2) lies_between (Y_axis(f2)).1, (Y_axis(f2)).(len f2); len f1 <> 0 & len f2 <> 0 by A1; then reconsider f1, f2 as non empty FinSequence of TOP-REAL 2 by FINSEQ_1:25 ; reconsider f = f1^f2 as non empty FinSequence of TOP-REAL 2; len f = len f1 + len f2 by FINSEQ_1:35; then A10: 2+2<=len f by A1,REAL_1:55; set G = GoB(f); now let n; assume A11: n in dom f1; then f/.n=f1/.n & dom f1 c= dom f by FINSEQ_1:39,GROUP_5:95; then consider i,j such that A12: [i,j] in Indices G & f/.n=G*(i,j) by A11,GOBOARD2:25; take i,j; thus [i,j] in Indices G & f1/.n=G*(i,j) by A11,A12,GROUP_5:95; end; then consider g1 such that A13: g1 is_sequence_on G & L~g1=L~f1 & g1/.1=f1/.1 & g1/.len g1=f1/.len f1 & len f1 <= len g1 by A2,A4,GOBOARD2:17; now let n; assume A14: n in dom f2; then f/.(len f1+n)=f2/.n & len f1+n in dom f by FINSEQ_1:41,GROUP_5:96; then consider i,j such that A15: [i,j] in Indices G & f/.(len f1+n)=G*(i,j) by GOBOARD2:25; take i,j; thus [i,j] in Indices G & f2/.n=G*(i,j) by A14,A15,GROUP_5:96; end; then consider g2 such that A16: g2 is_sequence_on G & L~g2=L~f2 & g2/.1=f2/.1 & g2/.len g2=f2/.len f2 & len f2 <= len g2 by A3,A5,GOBOARD2:17; set x = X_axis(f), y = Y_axis(f), x1 = X_axis(f1), y1 = Y_axis(f1), x2 = X_axis(f2), y2 = Y_axis(f2); A17: Seg len f1=dom f1 & Seg len f2=dom f2 & Seg len f=dom f & dom x = Seg len x & Seg len y = dom y & len x = len f & len y = len f & Seg len x1=dom x1 & Seg len y1=dom y1 & len x1=len f1 & len y1=len f1 & Seg len x2=dom x2 & Seg len y2=dom y2 & len x2=len f2 & len y2=len f2 & dom f1 c= dom f & rng f1 c= the carrier of TOP-REAL 2 & rng f2 c= the carrier of TOP-REAL 2 by FINSEQ_1:39,def 3,def 4,GOBOARD1:def 3,def 4; 1<=len f & 1<=len f1 & 1<=len f2 by A1,A10,AXIOMS:22; then A18: 1 in dom f & 1 in dom f1 & len f1 in dom f1 & 1 in dom f2 & len f2 in dom f2 by FINSEQ_3:27; then A19: f/.1=f1/.1 & f/.len f1=f1/.len f1 & f/.(len f1+1)=f2/.1 & f/.(len f1+len f2)=f2/.len f2 & len f1 in dom f & len f1+1 in dom f & len f1+len f2 in dom f by A17,FINSEQ_1:41,GROUP_5:95,96; reconsider p1=f1/.1, p2=f1/.len f1, q1=f2/.1, q2=f2/.len f2 as Point of TOP-REAL 2; A20: x.1=p1`1 & x1.1=p1`1 & x.(len f1) = p2`1 & x1.(len f1) = p2`1 & y.(len f1+1)=q1`2 & y2.1=q1`2 & y.(len f1+len f2)=q2`2 & y2.(len f2)=q2`2 by A17,A18,A19,GOBOARD1:def 3,def 4; A21: len f = len f1 + len f2 by FINSEQ_1:35; now let m; assume A22: m in dom f; then A23: 1<=m & m<=len f by FINSEQ_3:27; set s = x.m; now per cases; suppose m<=len f1; then A24: m in dom f1 by A23,FINSEQ_3:27; reconsider u=f1/.m as Point of TOP-REAL 2; f/.m=u by A24,GROUP_5:95; then A25: x.m=u`1 by A17,A22,GOBOARD1:def 3; x1.m=u`1 by A17,A24,GOBOARD1:def 3; hence p1`1<=s by A6,A17,A20,A24,A25,Def1; suppose A26: len f1<m; then reconsider w5 = m-len f1 as Nat by INT_1:18; A27: m = w5 + len f1 by XCMPLX_1:27; w5 > 0 by A26,SQUARE_1:11; then A28: 1<=w5 & w5<=len f2 by A21,A23,A27,REAL_1:53,RLVECT_1:99; then A29: f/.m = f2/.w5 & len f1 +1<=m by A26,A27,GOBOARD2:5,NAT_1:38; reconsider m1=m-len f1 as Nat by A27; A30: m1 in dom f2 by A28,FINSEQ_3:27; reconsider u=f2/.m1 as Point of TOP-REAL 2; A31: x.m=u`1 by A17,A22,A29,GOBOARD1:def 3; x2.m1=u`1 by A17,A30,GOBOARD1:def 3; hence p1`1<=s by A7,A17,A20,A30,A31,Def1; end; hence p1`1<=s; end; then A32: f/.1 in rng Line(G,1) by A18,A20,GOBOARD2:26; now let m; assume A33: m in dom f; then A34: 1<=m & m<=len f by FINSEQ_3:27; set s = x.m; now per cases; suppose m<=len f1; then A35: m in dom f1 by A34,FINSEQ_3:27; reconsider u=f1/.m as Point of TOP-REAL 2; f/.m=u by A35,GROUP_5:95; then A36: x.m=u`1 by A17,A33,GOBOARD1:def 3; x1.m=u`1 by A17,A35,GOBOARD1:def 3; hence s<=p2`1 by A6,A17,A20,A35,A36,Def1; suppose A37: len f1<m; then reconsider w5 = m-len f1 as Nat by INT_1:18; A38: m = w5 + len f1 by XCMPLX_1:27; w5 > 0 by A37,SQUARE_1:11; then A39: 1<=w5 & w5<=len f2 by A21,A34,A38,REAL_1:53,RLVECT_1:99; then A40: f/.m = f2/.w5 & len f1 +1<=m by A37,A38,GOBOARD2:5,NAT_1:38; reconsider m1=m-len f1 as Nat by A38; A41: m1 in dom f2 by A39,FINSEQ_3:27; reconsider u=f2/.m1 as Point of TOP-REAL 2; A42: x.m=u`1 by A17,A33,A40,GOBOARD1:def 3; x2.m1=u`1 by A17,A41,GOBOARD1:def 3; hence s<=p2`1 by A7,A17,A20,A41,A42,Def1; end; hence s<=p2`1; end; then A43: f/.len f1 in rng Line(G,len G) by A17,A18,A20,GOBOARD2:27; now let m; assume A44: m in dom f; then A45: 1<=m & m<=len f by FINSEQ_3:27; set s = y.m; now per cases; suppose m<=len f1; then A46: m in dom f1 by A45,FINSEQ_3:27; reconsider u=f1/.m as Point of TOP-REAL 2; f/.m=u by A46,GROUP_5:95; then A47: y.m=u`2 by A17,A44,GOBOARD1:def 4; y1.m=u`2 by A17,A46,GOBOARD1:def 4; hence q1`2<=s by A8,A17,A20,A46,A47,Def1; suppose A48: len f1<m; then reconsider w5 = m-len f1 as Nat by INT_1:18; A49: m = w5 + len f1 by XCMPLX_1:27; w5 > 0 by A48,SQUARE_1:11; then A50: 1<=w5 & w5<=len f2 by A21,A45,A49,REAL_1:53,RLVECT_1:99; then A51: f/.m = f2/.w5 & len f1 +1<=m by A48,A49,GOBOARD2:5,NAT_1:38; reconsider m1=m-len f1 as Nat by A49; A52: m1 in dom f2 by A50,FINSEQ_3:27; reconsider u=f2/.m1 as Point of TOP-REAL 2; A53: y.m=u`2 by A17,A44,A51,GOBOARD1:def 4; y2.m1=u`2 by A17,A52,GOBOARD1:def 4; hence q1`2<=s by A9,A17,A20,A52,A53,Def1; end; hence q1`2<=s; end; then A54: f/.(len f1+1) in rng Col(G,1) by A19,A20,GOBOARD2:28; now let m; assume A55: m in dom f; then A56: 1<=m & m<=len f by FINSEQ_3:27; set s = y.m; now per cases; suppose m<=len f1; then A57: m in dom f1 by A56,FINSEQ_3:27; reconsider u=f1/.m as Point of TOP-REAL 2; f/.m=u by A57,GROUP_5:95; then A58: y.m=u`2 by A17,A55,GOBOARD1:def 4; y1.m=u`2 by A17,A57,GOBOARD1:def 4; hence s<=q2`2 by A8,A17,A20,A57,A58,Def1; suppose A59: len f1<m; then reconsider w5 = m-len f1 as Nat by INT_1:18; A60: m = w5 + len f1 by XCMPLX_1:27; w5 > 0 by A59,SQUARE_1:11; then A61: 1<=w5 & w5<=len f2 by A21,A56,A60,REAL_1:53,RLVECT_1:99; then A62: f/.m = f2/.w5 & len f1 +1<=m by A59,A60,GOBOARD2:5,NAT_1:38; reconsider m1=m-len f1 as Nat by A60; A63: m1 in dom f2 by A61,FINSEQ_3:27; reconsider u=f2/.m1 as Point of TOP-REAL 2; A64: y.m=u`2 by A17,A55,A62,GOBOARD1:def 4; y2.m1=u`2 by A17,A63,GOBOARD1:def 4; hence s<=q2`2 by A9,A17,A20,A63,A64,Def1; end; hence s<=q2`2; end; then A65: f/.(len f1+len f2) in rng Col(G,width G) by A19,A20,GOBOARD2:29; 2<=len g1 & 2<=len g2 by A1,A13,A16,AXIOMS:22; hence thesis by A13,A16,A19,A32,A43,A54,A65,Th2; end; theorem Th5: for f1,f2 being FinSequence of TOP-REAL 2 st f1 is one-to-one special & 2 <= len f1 & f2 is one-to-one special & 2 <= len f2 & X_axis(f1) lies_between (X_axis(f1)).1, (X_axis(f1)).(len f1) & X_axis(f2) lies_between (X_axis(f1)).1, (X_axis(f1)).(len f1) & Y_axis(f1) lies_between (Y_axis(f2)).1, (Y_axis(f2)).(len f2) & Y_axis(f2) lies_between (Y_axis(f2)).1, (Y_axis(f2)).(len f2) holds L~f1 meets L~f2 proof let f1,f2 be FinSequence of TOP-REAL 2; assume that A1: f1 is one-to-one special & 2 <= len f1 & f2 is one-to-one special & 2 <= len f2 and A2: X_axis(f1) lies_between (X_axis(f1)).1, (X_axis(f1)).(len f1) and A3: X_axis(f2) lies_between (X_axis(f1)).1, (X_axis(f1)).(len f1) and A4: Y_axis(f1) lies_between (Y_axis(f2)).1, (Y_axis(f2)).(len f2) and A5: Y_axis(f2) lies_between (Y_axis(f2)).1, (Y_axis(f2)).(len f2); A6: for n st n in dom f1 & n+1 in dom f1 holds f1/.n <> f1/.(n+1) proof let n; assume n in dom f1 & n+1 in dom f1 & f1/.n=f1/.(n+1); then n=n+1 by A1,PARTFUN2:17; hence contradiction by NAT_1:38; end; for n st n in dom f2 & n+1 in dom f2 holds f2/.n <> f2/.(n+1) proof let n; assume n in dom f2 & n+1 in dom f2 & f2/.n=f2/.(n+1); then n=n+1 by A1,PARTFUN2:17; hence contradiction by NAT_1:38; end; hence thesis by A1,A2,A3,A4,A5,A6,Th4; end; canceled 2; theorem for P1,P2,p1,p2,q1,q2 st P1 is_S-P_arc_joining p1,q1 & P2 is_S-P_arc_joining p2,q2 & (for p st p in P1 \/ P2 holds p1`1<=p`1 & p`1<=q1`1) & (for p st p in P1 \/ P2 holds p2`2<=p`2 & p`2<=q2`2) holds P1 meets P2 proof let P1,P2,p1,p2,q1,q2; assume that A1: P1 is_S-P_arc_joining p1,q1 & P2 is_S-P_arc_joining p2,q2 and A2: for p st p in P1 \/ P2 holds p1`1<=p`1 & p`1<=q1`1 and A3: for p st p in P1 \/ P2 holds p2`2<=p`2 & p`2<=q2`2; consider f1 such that A4: f1 is_S-Seq & P1=L~f1 & p1=f1/.1 & q1=f1/.len f1 by A1,TOPREAL4:def 1; len f1 <> 0 by A4,TOPREAL1:def 10; then reconsider f1 as non empty FinSequence of TOP-REAL 2 by FINSEQ_1:25; consider f2 such that A5: f2 is_S-Seq & P2=L~f2 & p2=f2/.1 & q2=f2/.len f2 by A1,TOPREAL4:def 1; len f2 <> 0 by A5,TOPREAL1:def 10; then reconsider f2 as non empty FinSequence of TOP-REAL 2 by FINSEQ_1:25; A6:f1 is one-to-one special & f2 is one-to-one special by A4,A5,TOPREAL1:def 10; A7: 1<=2 & 2<=len f1 & 2<=len f2 by A4,A5,TOPREAL1:def 10; then 2<=len f1 & 2<=len f2 & 1<=len f1 & 1<=len f2 by AXIOMS:22; then A8: 1 in dom f1 & 1 in dom f2 & len f1 in dom f1 & len f2 in dom f2 by FINSEQ_3:27; set x1 = X_axis(f1), y1 = Y_axis(f1), x2 = X_axis(f2), y2 = Y_axis(f2); A9: Seg len f1=dom f1 & Seg len f2=dom f2 & Seg len x1=dom x1 & dom x2=Seg len x2 & dom y1=Seg len y1 & dom y2=Seg len y2 & len x1= len f1 & len y1=len f1 & len x2=len f2 & len y2=len f2 & rng f1 c=the carrier of TOP-REAL 2 & rng f2 c=the carrier of TOP-REAL 2 by FINSEQ_1:def 3,def 4,GOBOARD1:def 3,def 4; then A10: x1.1=p1`1 & x1.(len f1)=q1`1 & y2.1=p2`2 & y2.(len f2)=q2`2 by A4,A5,A8,GOBOARD1:def 3,def 4; A11: x1 lies_between x1.1, x1.len f1 proof let n; set q=f1/.n; assume A12: n in dom x1; then q in rng f1 & q in L~f1 by A7,A9,GOBOARD1:16,PARTFUN2:4; then x1.n=q`1 & q in P1 \/ P2 by A4,A12,GOBOARD1:def 3,XBOOLE_0:def 2; hence thesis by A2,A10; end; A13: x2 lies_between x1.1, x1.len f1 proof let n; set q=f2/.n; assume A14: n in dom x2; then q in rng f2 & q in L~f2 by A7,A9,GOBOARD1:16,PARTFUN2:4; then x2.n=q`1 & q in P1 \/ P2 by A5,A14,GOBOARD1:def 3,XBOOLE_0:def 2; hence thesis by A2,A10; end; A15: y1 lies_between y2.1, y2.len f2 proof let n; set q=f1/.n; assume A16: n in dom y1; then q in rng f1 & q in L~f1 by A7,A9,GOBOARD1:16,PARTFUN2:4; then y1.n=q`2 & q in P1 \/ P2 by A4,A16,GOBOARD1:def 4,XBOOLE_0:def 2; hence thesis by A3,A10; end; y2 lies_between y2.1, y2.len f2 proof let n; set q = f2/.n; assume A17: n in dom y2; then q in rng f2 & q in L~f2 by A7,A9,GOBOARD1:16,PARTFUN2:4; then y2.n=q`2 & q in P1 \/ P2 by A5,A17,GOBOARD1:def 4,XBOOLE_0:def 2; hence thesis by A3,A10; end; hence thesis by A4,A5,A6,A7,A11,A13,A15,Th5; end;